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/*
* Copyright (c) 2006 - 2009 Mellanox Technology Inc. All rights reserved.
* Copyright (C) 2008 - 2011 Bart Van Assche <bvanassche@acm.org>.
*
* 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/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/ctype.h>
#include <linux/kthread.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/atomic.h>
#include <linux/inet.h>
#include <rdma/ib_cache.h>
#include <scsi/scsi_proto.h>
#include <scsi/scsi_tcq.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include "ib_srpt.h"
/* Name of this kernel module. */
#define DRV_NAME "ib_srpt"
#define SRPT_ID_STRING "Linux SRP target"
#undef pr_fmt
#define pr_fmt(fmt) DRV_NAME " " fmt
MODULE_AUTHOR("Vu Pham and Bart Van Assche");
MODULE_DESCRIPTION("SCSI RDMA Protocol target driver");
MODULE_LICENSE("Dual BSD/GPL");
/*
* Global Variables
*/
static u64 srpt_service_guid;
static DEFINE_SPINLOCK(srpt_dev_lock); /* Protects srpt_dev_list. */
static LIST_HEAD(srpt_dev_list); /* List of srpt_device structures. */
static unsigned srp_max_req_size = DEFAULT_MAX_REQ_SIZE;
module_param(srp_max_req_size, int, 0444);
MODULE_PARM_DESC(srp_max_req_size,
"Maximum size of SRP request messages in bytes.");
static int srpt_srq_size = DEFAULT_SRPT_SRQ_SIZE;
module_param(srpt_srq_size, int, 0444);
MODULE_PARM_DESC(srpt_srq_size,
"Shared receive queue (SRQ) size.");
static int srpt_get_u64_x(char *buffer, const struct kernel_param *kp)
{
return sprintf(buffer, "0x%016llx", *(u64 *)kp->arg);
}
module_param_call(srpt_service_guid, NULL, srpt_get_u64_x, &srpt_service_guid,
0444);
MODULE_PARM_DESC(srpt_service_guid,
"Using this value for ioc_guid, id_ext, and cm_listen_id instead of using the node_guid of the first HCA.");
static struct ib_client srpt_client;
/* Protects both rdma_cm_port and rdma_cm_id. */
static DEFINE_MUTEX(rdma_cm_mutex);
/* Port number RDMA/CM will bind to. */
static u16 rdma_cm_port;
static struct rdma_cm_id *rdma_cm_id;
static void srpt_release_cmd(struct se_cmd *se_cmd);
static void srpt_free_ch(struct kref *kref);
static int srpt_queue_status(struct se_cmd *cmd);
static void srpt_recv_done(struct ib_cq *cq, struct ib_wc *wc);
static void srpt_send_done(struct ib_cq *cq, struct ib_wc *wc);
static void srpt_process_wait_list(struct srpt_rdma_ch *ch);
/*
* The only allowed channel state changes are those that change the channel
* state into a state with a higher numerical value. Hence the new > prev test.
*/
static bool srpt_set_ch_state(struct srpt_rdma_ch *ch, enum rdma_ch_state new)
{
unsigned long flags;
enum rdma_ch_state prev;
bool changed = false;
spin_lock_irqsave(&ch->spinlock, flags);
prev = ch->state;
if (new > prev) {
ch->state = new;
changed = true;
}
spin_unlock_irqrestore(&ch->spinlock, flags);
return changed;
}
/**
* srpt_event_handler - asynchronous IB event callback function
* @handler: IB event handler registered by ib_register_event_handler().
* @event: Description of the event that occurred.
*
* Callback function called by the InfiniBand core when an asynchronous IB
* event occurs. This callback may occur in interrupt context. See also
* section 11.5.2, Set Asynchronous Event Handler in the InfiniBand
* Architecture Specification.
*/
static void srpt_event_handler(struct ib_event_handler *handler,
struct ib_event *event)
{
struct srpt_device *sdev;
struct srpt_port *sport;
u8 port_num;
sdev = ib_get_client_data(event->device, &srpt_client);
if (!sdev || sdev->device != event->device)
return;
pr_debug("ASYNC event= %d on device= %s\n", event->event,
dev_name(&sdev->device->dev));
switch (event->event) {
case IB_EVENT_PORT_ERR:
port_num = event->element.port_num - 1;
if (port_num < sdev->device->phys_port_cnt) {
sport = &sdev->port[port_num];
sport->lid = 0;
sport->sm_lid = 0;
} else {
WARN(true, "event %d: port_num %d out of range 1..%d\n",
event->event, port_num + 1,
sdev->device->phys_port_cnt);
}
break;
case IB_EVENT_PORT_ACTIVE:
case IB_EVENT_LID_CHANGE:
case IB_EVENT_PKEY_CHANGE:
case IB_EVENT_SM_CHANGE:
case IB_EVENT_CLIENT_REREGISTER:
case IB_EVENT_GID_CHANGE:
/* Refresh port data asynchronously. */
port_num = event->element.port_num - 1;
if (port_num < sdev->device->phys_port_cnt) {
sport = &sdev->port[port_num];
if (!sport->lid && !sport->sm_lid)
schedule_work(&sport->work);
} else {
WARN(true, "event %d: port_num %d out of range 1..%d\n",
event->event, port_num + 1,
sdev->device->phys_port_cnt);
}
break;
default:
pr_err("received unrecognized IB event %d\n", event->event);
break;
}
}
/**
* srpt_srq_event - SRQ event callback function
* @event: Description of the event that occurred.
* @ctx: Context pointer specified at SRQ creation time.
*/
static void srpt_srq_event(struct ib_event *event, void *ctx)
{
pr_debug("SRQ event %d\n", event->event);
}
static const char *get_ch_state_name(enum rdma_ch_state s)
{
switch (s) {
case CH_CONNECTING:
return "connecting";
case CH_LIVE:
return "live";
case CH_DISCONNECTING:
return "disconnecting";
case CH_DRAINING:
return "draining";
case CH_DISCONNECTED:
return "disconnected";
}
return "???";
}
/**
* srpt_qp_event - QP event callback function
* @event: Description of the event that occurred.
* @ch: SRPT RDMA channel.
*/
static void srpt_qp_event(struct ib_event *event, struct srpt_rdma_ch *ch)
{
pr_debug("QP event %d on ch=%p sess_name=%s state=%d\n",
event->event, ch, ch->sess_name, ch->state);
switch (event->event) {
case IB_EVENT_COMM_EST:
if (ch->using_rdma_cm)
rdma_notify(ch->rdma_cm.cm_id, event->event);
else
ib_cm_notify(ch->ib_cm.cm_id, event->event);
break;
case IB_EVENT_QP_LAST_WQE_REACHED:
pr_debug("%s-%d, state %s: received Last WQE event.\n",
ch->sess_name, ch->qp->qp_num,
get_ch_state_name(ch->state));
break;
default:
pr_err("received unrecognized IB QP event %d\n", event->event);
break;
}
}
/**
* srpt_set_ioc - initialize a IOUnitInfo structure
* @c_list: controller list.
* @slot: one-based slot number.
* @value: four-bit value.
*
* Copies the lowest four bits of value in element slot of the array of four
* bit elements called c_list (controller list). The index slot is one-based.
*/
static void srpt_set_ioc(u8 *c_list, u32 slot, u8 value)
{
u16 id;
u8 tmp;
id = (slot - 1) / 2;
if (slot & 0x1) {
tmp = c_list[id] & 0xf;
c_list[id] = (value << 4) | tmp;
} else {
tmp = c_list[id] & 0xf0;
c_list[id] = (value & 0xf) | tmp;
}
}
/**
* srpt_get_class_port_info - copy ClassPortInfo to a management datagram
* @mad: Datagram that will be sent as response to DM_ATTR_CLASS_PORT_INFO.
*
* See also section 16.3.3.1 ClassPortInfo in the InfiniBand Architecture
* Specification.
*/
static void srpt_get_class_port_info(struct ib_dm_mad *mad)
{
struct ib_class_port_info *cif;
cif = (struct ib_class_port_info *)mad->data;
memset(cif, 0, sizeof(*cif));
cif->base_version = 1;
cif->class_version = 1;
ib_set_cpi_resp_time(cif, 20);
mad->mad_hdr.status = 0;
}
/**
* srpt_get_iou - write IOUnitInfo to a management datagram
* @mad: Datagram that will be sent as response to DM_ATTR_IOU_INFO.
*
* See also section 16.3.3.3 IOUnitInfo in the InfiniBand Architecture
* Specification. See also section B.7, table B.6 in the SRP r16a document.
*/
static void srpt_get_iou(struct ib_dm_mad *mad)
{
struct ib_dm_iou_info *ioui;
u8 slot;
int i;
ioui = (struct ib_dm_iou_info *)mad->data;
ioui->change_id = cpu_to_be16(1);
ioui->max_controllers = 16;
/* set present for slot 1 and empty for the rest */
srpt_set_ioc(ioui->controller_list, 1, 1);
for (i = 1, slot = 2; i < 16; i++, slot++)
srpt_set_ioc(ioui->controller_list, slot, 0);
mad->mad_hdr.status = 0;
}
/**
* srpt_get_ioc - write IOControllerprofile to a management datagram
* @sport: HCA port through which the MAD has been received.
* @slot: Slot number specified in DM_ATTR_IOC_PROFILE query.
* @mad: Datagram that will be sent as response to DM_ATTR_IOC_PROFILE.
*
* See also section 16.3.3.4 IOControllerProfile in the InfiniBand
* Architecture Specification. See also section B.7, table B.7 in the SRP
* r16a document.
*/
static void srpt_get_ioc(struct srpt_port *sport, u32 slot,
struct ib_dm_mad *mad)
{
struct srpt_device *sdev = sport->sdev;
struct ib_dm_ioc_profile *iocp;
int send_queue_depth;
iocp = (struct ib_dm_ioc_profile *)mad->data;
if (!slot || slot > 16) {
mad->mad_hdr.status
= cpu_to_be16(DM_MAD_STATUS_INVALID_FIELD);
return;
}
if (slot > 2) {
mad->mad_hdr.status
= cpu_to_be16(DM_MAD_STATUS_NO_IOC);
return;
}
if (sdev->use_srq)
send_queue_depth = sdev->srq_size;
else
send_queue_depth = min(MAX_SRPT_RQ_SIZE,
sdev->device->attrs.max_qp_wr);
memset(iocp, 0, sizeof(*iocp));
strcpy(iocp->id_string, SRPT_ID_STRING);
iocp->guid = cpu_to_be64(srpt_service_guid);
iocp->vendor_id = cpu_to_be32(sdev->device->attrs.vendor_id);
iocp->device_id = cpu_to_be32(sdev->device->attrs.vendor_part_id);
iocp->device_version = cpu_to_be16(sdev->device->attrs.hw_ver);
iocp->subsys_vendor_id = cpu_to_be32(sdev->device->attrs.vendor_id);
iocp->subsys_device_id = 0x0;
iocp->io_class = cpu_to_be16(SRP_REV16A_IB_IO_CLASS);
iocp->io_subclass = cpu_to_be16(SRP_IO_SUBCLASS);
iocp->protocol = cpu_to_be16(SRP_PROTOCOL);
iocp->protocol_version = cpu_to_be16(SRP_PROTOCOL_VERSION);
iocp->send_queue_depth = cpu_to_be16(send_queue_depth);
iocp->rdma_read_depth = 4;
iocp->send_size = cpu_to_be32(srp_max_req_size);
iocp->rdma_size = cpu_to_be32(min(sport->port_attrib.srp_max_rdma_size,
1U << 24));
iocp->num_svc_entries = 1;
iocp->op_cap_mask = SRP_SEND_TO_IOC | SRP_SEND_FROM_IOC |
SRP_RDMA_READ_FROM_IOC | SRP_RDMA_WRITE_FROM_IOC;
mad->mad_hdr.status = 0;
}
/**
* srpt_get_svc_entries - write ServiceEntries to a management datagram
* @ioc_guid: I/O controller GUID to use in reply.
* @slot: I/O controller number.
* @hi: End of the range of service entries to be specified in the reply.
* @lo: Start of the range of service entries to be specified in the reply..
* @mad: Datagram that will be sent as response to DM_ATTR_SVC_ENTRIES.
*
* See also section 16.3.3.5 ServiceEntries in the InfiniBand Architecture
* Specification. See also section B.7, table B.8 in the SRP r16a document.
*/
static void srpt_get_svc_entries(u64 ioc_guid,
u16 slot, u8 hi, u8 lo, struct ib_dm_mad *mad)
{
struct ib_dm_svc_entries *svc_entries;
WARN_ON(!ioc_guid);
if (!slot || slot > 16) {
mad->mad_hdr.status
= cpu_to_be16(DM_MAD_STATUS_INVALID_FIELD);
return;
}
if (slot > 2 || lo > hi || hi > 1) {
mad->mad_hdr.status
= cpu_to_be16(DM_MAD_STATUS_NO_IOC);
return;
}
svc_entries = (struct ib_dm_svc_entries *)mad->data;
memset(svc_entries, 0, sizeof(*svc_entries));
svc_entries->service_entries[0].id = cpu_to_be64(ioc_guid);
snprintf(svc_entries->service_entries[0].name,
sizeof(svc_entries->service_entries[0].name),
"%s%016llx",
SRP_SERVICE_NAME_PREFIX,
ioc_guid);
mad->mad_hdr.status = 0;
}
/**
* srpt_mgmt_method_get - process a received management datagram
* @sp: HCA port through which the MAD has been received.
* @rq_mad: received MAD.
* @rsp_mad: response MAD.
*/
static void srpt_mgmt_method_get(struct srpt_port *sp, struct ib_mad *rq_mad,
struct ib_dm_mad *rsp_mad)
{
u16 attr_id;
u32 slot;
u8 hi, lo;
attr_id = be16_to_cpu(rq_mad->mad_hdr.attr_id);
switch (attr_id) {
case DM_ATTR_CLASS_PORT_INFO:
srpt_get_class_port_info(rsp_mad);
break;
case DM_ATTR_IOU_INFO:
srpt_get_iou(rsp_mad);
break;
case DM_ATTR_IOC_PROFILE:
slot = be32_to_cpu(rq_mad->mad_hdr.attr_mod);
srpt_get_ioc(sp, slot, rsp_mad);
break;
case DM_ATTR_SVC_ENTRIES:
slot = be32_to_cpu(rq_mad->mad_hdr.attr_mod);
hi = (u8) ((slot >> 8) & 0xff);
lo = (u8) (slot & 0xff);
slot = (u16) ((slot >> 16) & 0xffff);
srpt_get_svc_entries(srpt_service_guid,
slot, hi, lo, rsp_mad);
break;
default:
rsp_mad->mad_hdr.status =
cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD_ATTR);
break;
}
}
/**
* srpt_mad_send_handler - MAD send completion callback
* @mad_agent: Return value of ib_register_mad_agent().
* @mad_wc: Work completion reporting that the MAD has been sent.
*/
static void srpt_mad_send_handler(struct ib_mad_agent *mad_agent,
struct ib_mad_send_wc *mad_wc)
{
rdma_destroy_ah(mad_wc->send_buf->ah, RDMA_DESTROY_AH_SLEEPABLE);
ib_free_send_mad(mad_wc->send_buf);
}
/**
* srpt_mad_recv_handler - MAD reception callback function
* @mad_agent: Return value of ib_register_mad_agent().
* @send_buf: Not used.
* @mad_wc: Work completion reporting that a MAD has been received.
*/
static void srpt_mad_recv_handler(struct ib_mad_agent *mad_agent,
struct ib_mad_send_buf *send_buf,
struct ib_mad_recv_wc *mad_wc)
{
struct srpt_port *sport = (struct srpt_port *)mad_agent->context;
struct ib_ah *ah;
struct ib_mad_send_buf *rsp;
struct ib_dm_mad *dm_mad;
if (!mad_wc || !mad_wc->recv_buf.mad)
return;
ah = ib_create_ah_from_wc(mad_agent->qp->pd, mad_wc->wc,
mad_wc->recv_buf.grh, mad_agent->port_num);
if (IS_ERR(ah))
goto err;
BUILD_BUG_ON(offsetof(struct ib_dm_mad, data) != IB_MGMT_DEVICE_HDR);
rsp = ib_create_send_mad(mad_agent, mad_wc->wc->src_qp,
mad_wc->wc->pkey_index, 0,
IB_MGMT_DEVICE_HDR, IB_MGMT_DEVICE_DATA,
GFP_KERNEL,
IB_MGMT_BASE_VERSION);
if (IS_ERR(rsp))
goto err_rsp;
rsp->ah = ah;
dm_mad = rsp->mad;
memcpy(dm_mad, mad_wc->recv_buf.mad, sizeof(*dm_mad));
dm_mad->mad_hdr.method = IB_MGMT_METHOD_GET_RESP;
dm_mad->mad_hdr.status = 0;
switch (mad_wc->recv_buf.mad->mad_hdr.method) {
case IB_MGMT_METHOD_GET:
srpt_mgmt_method_get(sport, mad_wc->recv_buf.mad, dm_mad);
break;
case IB_MGMT_METHOD_SET:
dm_mad->mad_hdr.status =
cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD_ATTR);
break;
default:
dm_mad->mad_hdr.status =
cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD);
break;
}
if (!ib_post_send_mad(rsp, NULL)) {
ib_free_recv_mad(mad_wc);
/* will destroy_ah & free_send_mad in send completion */
return;
}
ib_free_send_mad(rsp);
err_rsp:
rdma_destroy_ah(ah, RDMA_DESTROY_AH_SLEEPABLE);
err:
ib_free_recv_mad(mad_wc);
}
static int srpt_format_guid(char *buf, unsigned int size, const __be64 *guid)
{
const __be16 *g = (const __be16 *)guid;
return snprintf(buf, size, "%04x:%04x:%04x:%04x",
be16_to_cpu(g[0]), be16_to_cpu(g[1]),
be16_to_cpu(g[2]), be16_to_cpu(g[3]));
}
/**
* srpt_refresh_port - configure a HCA port
* @sport: SRPT HCA port.
*
* Enable InfiniBand management datagram processing, update the cached sm_lid,
* lid and gid values, and register a callback function for processing MADs
* on the specified port.
*
* Note: It is safe to call this function more than once for the same port.
*/
static int srpt_refresh_port(struct srpt_port *sport)
{
struct ib_mad_reg_req reg_req;
struct ib_port_modify port_modify;
struct ib_port_attr port_attr;
int ret;
ret = ib_query_port(sport->sdev->device, sport->port, &port_attr);
if (ret)
return ret;
sport->sm_lid = port_attr.sm_lid;
sport->lid = port_attr.lid;
ret = rdma_query_gid(sport->sdev->device, sport->port, 0, &sport->gid);
if (ret)
return ret;
sport->port_guid_id.wwn.priv = sport;
srpt_format_guid(sport->port_guid_id.name,
sizeof(sport->port_guid_id.name),
&sport->gid.global.interface_id);
sport->port_gid_id.wwn.priv = sport;
snprintf(sport->port_gid_id.name, sizeof(sport->port_gid_id.name),
"0x%016llx%016llx",
be64_to_cpu(sport->gid.global.subnet_prefix),
be64_to_cpu(sport->gid.global.interface_id));
if (rdma_protocol_iwarp(sport->sdev->device, sport->port))
return 0;
memset(&port_modify, 0, sizeof(port_modify));
port_modify.set_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP;
port_modify.clr_port_cap_mask = 0;
ret = ib_modify_port(sport->sdev->device, sport->port, 0, &port_modify);
if (ret) {
pr_warn("%s-%d: enabling device management failed (%d). Note: this is expected if SR-IOV is enabled.\n",
dev_name(&sport->sdev->device->dev), sport->port, ret);
return 0;
}
if (!sport->mad_agent) {
memset(&reg_req, 0, sizeof(reg_req));
reg_req.mgmt_class = IB_MGMT_CLASS_DEVICE_MGMT;
reg_req.mgmt_class_version = IB_MGMT_BASE_VERSION;
set_bit(IB_MGMT_METHOD_GET, reg_req.method_mask);
set_bit(IB_MGMT_METHOD_SET, reg_req.method_mask);
sport->mad_agent = ib_register_mad_agent(sport->sdev->device,
sport->port,
IB_QPT_GSI,
&reg_req, 0,
srpt_mad_send_handler,
srpt_mad_recv_handler,
sport, 0);
if (IS_ERR(sport->mad_agent)) {
pr_err("%s-%d: MAD agent registration failed (%ld). Note: this is expected if SR-IOV is enabled.\n",
dev_name(&sport->sdev->device->dev), sport->port,
PTR_ERR(sport->mad_agent));
sport->mad_agent = NULL;
}
}
return 0;
}
/**
* srpt_unregister_mad_agent - unregister MAD callback functions
* @sdev: SRPT HCA pointer.
*
* Note: It is safe to call this function more than once for the same device.
*/
static void srpt_unregister_mad_agent(struct srpt_device *sdev)
{
struct ib_port_modify port_modify = {
.clr_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP,
};
struct srpt_port *sport;
int i;
for (i = 1; i <= sdev->device->phys_port_cnt; i++) {
sport = &sdev->port[i - 1];
WARN_ON(sport->port != i);
if (ib_modify_port(sdev->device, i, 0, &port_modify) < 0)
pr_err("disabling MAD processing failed.\n");
if (sport->mad_agent) {
ib_unregister_mad_agent(sport->mad_agent);
sport->mad_agent = NULL;
}
}
}
/**
* srpt_alloc_ioctx - allocate a SRPT I/O context structure
* @sdev: SRPT HCA pointer.
* @ioctx_size: I/O context size.
* @buf_cache: I/O buffer cache.
* @dir: DMA data direction.
*/
static struct srpt_ioctx *srpt_alloc_ioctx(struct srpt_device *sdev,
int ioctx_size,
struct kmem_cache *buf_cache,
enum dma_data_direction dir)
{
struct srpt_ioctx *ioctx;
ioctx = kzalloc(ioctx_size, GFP_KERNEL);
if (!ioctx)
goto err;
ioctx->buf = kmem_cache_alloc(buf_cache, GFP_KERNEL);
if (!ioctx->buf)
goto err_free_ioctx;
ioctx->dma = ib_dma_map_single(sdev->device, ioctx->buf,
kmem_cache_size(buf_cache), dir);
if (ib_dma_mapping_error(sdev->device, ioctx->dma))
goto err_free_buf;
return ioctx;
err_free_buf:
kmem_cache_free(buf_cache, ioctx->buf);
err_free_ioctx:
kfree(ioctx);
err:
return NULL;
}
/**
* srpt_free_ioctx - free a SRPT I/O context structure
* @sdev: SRPT HCA pointer.
* @ioctx: I/O context pointer.
* @buf_cache: I/O buffer cache.
* @dir: DMA data direction.
*/
static void srpt_free_ioctx(struct srpt_device *sdev, struct srpt_ioctx *ioctx,
struct kmem_cache *buf_cache,
enum dma_data_direction dir)
{
if (!ioctx)
return;
ib_dma_unmap_single(sdev->device, ioctx->dma,
kmem_cache_size(buf_cache), dir);
kmem_cache_free(buf_cache, ioctx->buf);
kfree(ioctx);
}
/**
* srpt_alloc_ioctx_ring - allocate a ring of SRPT I/O context structures
* @sdev: Device to allocate the I/O context ring for.
* @ring_size: Number of elements in the I/O context ring.
* @ioctx_size: I/O context size.
* @buf_cache: I/O buffer cache.
* @alignment_offset: Offset in each ring buffer at which the SRP information
* unit starts.
* @dir: DMA data direction.
*/
static struct srpt_ioctx **srpt_alloc_ioctx_ring(struct srpt_device *sdev,
int ring_size, int ioctx_size,
struct kmem_cache *buf_cache,
int alignment_offset,
enum dma_data_direction dir)
{
struct srpt_ioctx **ring;
int i;
WARN_ON(ioctx_size != sizeof(struct srpt_recv_ioctx) &&
ioctx_size != sizeof(struct srpt_send_ioctx));
ring = kvmalloc_array(ring_size, sizeof(ring[0]), GFP_KERNEL);
if (!ring)
goto out;
for (i = 0; i < ring_size; ++i) {
ring[i] = srpt_alloc_ioctx(sdev, ioctx_size, buf_cache, dir);
if (!ring[i])
goto err;
ring[i]->index = i;
ring[i]->offset = alignment_offset;
}
goto out;
err:
while (--i >= 0)
srpt_free_ioctx(sdev, ring[i], buf_cache, dir);
kvfree(ring);
ring = NULL;
out:
return ring;
}
/**
* srpt_free_ioctx_ring - free the ring of SRPT I/O context structures
* @ioctx_ring: I/O context ring to be freed.
* @sdev: SRPT HCA pointer.
* @ring_size: Number of ring elements.
* @buf_cache: I/O buffer cache.
* @dir: DMA data direction.
*/
static void srpt_free_ioctx_ring(struct srpt_ioctx **ioctx_ring,
struct srpt_device *sdev, int ring_size,
struct kmem_cache *buf_cache,
enum dma_data_direction dir)
{
int i;
if (!ioctx_ring)
return;
for (i = 0; i < ring_size; ++i)
srpt_free_ioctx(sdev, ioctx_ring[i], buf_cache, dir);
kvfree(ioctx_ring);
}
/**
* srpt_set_cmd_state - set the state of a SCSI command
* @ioctx: Send I/O context.
* @new: New I/O context state.
*
* Does not modify the state of aborted commands. Returns the previous command
* state.
*/
static enum srpt_command_state srpt_set_cmd_state(struct srpt_send_ioctx *ioctx,
enum srpt_command_state new)
{
enum srpt_command_state previous;
previous = ioctx->state;
if (previous != SRPT_STATE_DONE)
ioctx->state = new;
return previous;
}
/**
* srpt_test_and_set_cmd_state - test and set the state of a command
* @ioctx: Send I/O context.
* @old: Current I/O context state.
* @new: New I/O context state.
*
* Returns true if and only if the previous command state was equal to 'old'.
*/
static bool srpt_test_and_set_cmd_state(struct srpt_send_ioctx *ioctx,
enum srpt_command_state old,
enum srpt_command_state new)
{
enum srpt_command_state previous;
WARN_ON(!ioctx);
WARN_ON(old == SRPT_STATE_DONE);
WARN_ON(new == SRPT_STATE_NEW);
previous = ioctx->state;
if (previous == old)
ioctx->state = new;
return previous == old;
}
/**
* srpt_post_recv - post an IB receive request
* @sdev: SRPT HCA pointer.
* @ch: SRPT RDMA channel.
* @ioctx: Receive I/O context pointer.
*/
static int srpt_post_recv(struct srpt_device *sdev, struct srpt_rdma_ch *ch,
struct srpt_recv_ioctx *ioctx)
{
struct ib_sge list;
struct ib_recv_wr wr;
BUG_ON(!sdev);
list.addr = ioctx->ioctx.dma + ioctx->ioctx.offset;
list.length = srp_max_req_size;
list.lkey = sdev->lkey;
ioctx->ioctx.cqe.done = srpt_recv_done;
wr.wr_cqe = &ioctx->ioctx.cqe;
wr.next = NULL;
wr.sg_list = &list;
wr.num_sge = 1;
if (sdev->use_srq)
return ib_post_srq_recv(sdev->srq, &wr, NULL);
else
return ib_post_recv(ch->qp, &wr, NULL);
}
/**
* srpt_zerolength_write - perform a zero-length RDMA write
* @ch: SRPT RDMA channel.
*
* A quote from the InfiniBand specification: C9-88: For an HCA responder
* using Reliable Connection service, for each zero-length RDMA READ or WRITE
* request, the R_Key shall not be validated, even if the request includes
* Immediate data.
*/
static int srpt_zerolength_write(struct srpt_rdma_ch *ch)
{
struct ib_rdma_wr wr = {
.wr = {
.next = NULL,
{ .wr_cqe = &ch->zw_cqe, },
.opcode = IB_WR_RDMA_WRITE,
.send_flags = IB_SEND_SIGNALED,
}
};
pr_debug("%s-%d: queued zerolength write\n", ch->sess_name,
ch->qp->qp_num);
return ib_post_send(ch->qp, &wr.wr, NULL);
}
static void srpt_zerolength_write_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct srpt_rdma_ch *ch = cq->cq_context;
pr_debug("%s-%d wc->status %d\n", ch->sess_name, ch->qp->qp_num,
wc->status);
if (wc->status == IB_WC_SUCCESS) {
srpt_process_wait_list(ch);
} else {
if (srpt_set_ch_state(ch, CH_DISCONNECTED))
schedule_work(&ch->release_work);
else
pr_debug("%s-%d: already disconnected.\n",
ch->sess_name, ch->qp->qp_num);
}
}
static int srpt_alloc_rw_ctxs(struct srpt_send_ioctx *ioctx,
struct srp_direct_buf *db, int nbufs, struct scatterlist **sg,
unsigned *sg_cnt)
{
enum dma_data_direction dir = target_reverse_dma_direction(&ioctx->cmd);
struct srpt_rdma_ch *ch = ioctx->ch;
struct scatterlist *prev = NULL;
unsigned prev_nents;
int ret, i;
if (nbufs == 1) {
ioctx->rw_ctxs = &ioctx->s_rw_ctx;
} else {
ioctx->rw_ctxs = kmalloc_array(nbufs, sizeof(*ioctx->rw_ctxs),
GFP_KERNEL);
if (!ioctx->rw_ctxs)
return -ENOMEM;
}
for (i = ioctx->n_rw_ctx; i < nbufs; i++, db++) {
struct srpt_rw_ctx *ctx = &ioctx->rw_ctxs[i];
u64 remote_addr = be64_to_cpu(db->va);
u32 size = be32_to_cpu(db->len);
u32 rkey = be32_to_cpu(db->key);
ret = target_alloc_sgl(&ctx->sg, &ctx->nents, size, false,
i < nbufs - 1);
if (ret)
goto unwind;
ret = rdma_rw_ctx_init(&ctx->rw, ch->qp, ch->sport->port,
ctx->sg, ctx->nents, 0, remote_addr, rkey, dir);
if (ret < 0) {
target_free_sgl(ctx->sg, ctx->nents);
goto unwind;
}
ioctx->n_rdma += ret;
ioctx->n_rw_ctx++;
if (prev) {
sg_unmark_end(&prev[prev_nents - 1]);
sg_chain(prev, prev_nents + 1, ctx->sg);
} else {
*sg = ctx->sg;
}
prev = ctx->sg;
prev_nents = ctx->nents;
*sg_cnt += ctx->nents;
}
return 0;
unwind:
while (--i >= 0) {
struct srpt_rw_ctx *ctx = &ioctx->rw_ctxs[i];
rdma_rw_ctx_destroy(&ctx->rw, ch->qp, ch->sport->port,
ctx->sg, ctx->nents, dir);
target_free_sgl(ctx->sg, ctx->nents);
}
if (ioctx->rw_ctxs != &ioctx->s_rw_ctx)
kfree(ioctx->rw_ctxs);
return ret;
}
static void srpt_free_rw_ctxs(struct srpt_rdma_ch *ch,
struct srpt_send_ioctx *ioctx)
{
enum dma_data_direction dir = target_reverse_dma_direction(&ioctx->cmd);
int i;
for (i = 0; i < ioctx->n_rw_ctx; i++) {
struct srpt_rw_ctx *ctx = &ioctx->rw_ctxs[i];
rdma_rw_ctx_destroy(&ctx->rw, ch->qp, ch->sport->port,
ctx->sg, ctx->nents, dir);
target_free_sgl(ctx->sg, ctx->nents);
}
if (ioctx->rw_ctxs != &ioctx->s_rw_ctx)
kfree(ioctx->rw_ctxs);
}
static inline void *srpt_get_desc_buf(struct srp_cmd *srp_cmd)
{
/*
* The pointer computations below will only be compiled correctly
* if srp_cmd::add_data is declared as s8*, u8*, s8[] or u8[], so check
* whether srp_cmd::add_data has been declared as a byte pointer.
*/
BUILD_BUG_ON(!__same_type(srp_cmd->add_data[0], (s8)0) &&
!__same_type(srp_cmd->add_data[0], (u8)0));
/*
* According to the SRP spec, the lower two bits of the 'ADDITIONAL
* CDB LENGTH' field are reserved and the size in bytes of this field
* is four times the value specified in bits 3..7. Hence the "& ~3".
*/
return srp_cmd->add_data + (srp_cmd->add_cdb_len & ~3);
}
/**
* srpt_get_desc_tbl - parse the data descriptors of a SRP_CMD request
* @recv_ioctx: I/O context associated with the received command @srp_cmd.
* @ioctx: I/O context that will be used for responding to the initiator.
* @srp_cmd: Pointer to the SRP_CMD request data.
* @dir: Pointer to the variable to which the transfer direction will be
* written.
* @sg: [out] scatterlist for the parsed SRP_CMD.
* @sg_cnt: [out] length of @sg.
* @data_len: Pointer to the variable to which the total data length of all
* descriptors in the SRP_CMD request will be written.
* @imm_data_offset: [in] Offset in SRP_CMD requests at which immediate data
* starts.
*
* This function initializes ioctx->nrbuf and ioctx->r_bufs.
*
* Returns -EINVAL when the SRP_CMD request contains inconsistent descriptors;
* -ENOMEM when memory allocation fails and zero upon success.
*/
static int srpt_get_desc_tbl(struct srpt_recv_ioctx *recv_ioctx,
struct srpt_send_ioctx *ioctx,
struct srp_cmd *srp_cmd, enum dma_data_direction *dir,
struct scatterlist **sg, unsigned int *sg_cnt, u64 *data_len,
u16 imm_data_offset)
{
BUG_ON(!dir);
BUG_ON(!data_len);
/*
* The lower four bits of the buffer format field contain the DATA-IN
* buffer descriptor format, and the highest four bits contain the
* DATA-OUT buffer descriptor format.
*/
if (srp_cmd->buf_fmt & 0xf)
/* DATA-IN: transfer data from target to initiator (read). */
*dir = DMA_FROM_DEVICE;
else if (srp_cmd->buf_fmt >> 4)
/* DATA-OUT: transfer data from initiator to target (write). */
*dir = DMA_TO_DEVICE;
else
*dir = DMA_NONE;
/* initialize data_direction early as srpt_alloc_rw_ctxs needs it */
ioctx->cmd.data_direction = *dir;
if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_DIRECT) ||
((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_DIRECT)) {
struct srp_direct_buf *db = srpt_get_desc_buf(srp_cmd);
*data_len = be32_to_cpu(db->len);
return srpt_alloc_rw_ctxs(ioctx, db, 1, sg, sg_cnt);
} else if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_INDIRECT) ||
((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_INDIRECT)) {
struct srp_indirect_buf *idb = srpt_get_desc_buf(srp_cmd);
int nbufs = be32_to_cpu(idb->table_desc.len) /
sizeof(struct srp_direct_buf);
if (nbufs >
(srp_cmd->data_out_desc_cnt + srp_cmd->data_in_desc_cnt)) {
pr_err("received unsupported SRP_CMD request type (%u out + %u in != %u / %zu)\n",
srp_cmd->data_out_desc_cnt,
srp_cmd->data_in_desc_cnt,
be32_to_cpu(idb->table_desc.len),
sizeof(struct srp_direct_buf));
return -EINVAL;
}
*data_len = be32_to_cpu(idb->len);
return srpt_alloc_rw_ctxs(ioctx, idb->desc_list, nbufs,
sg, sg_cnt);
} else if ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_IMM) {
struct srp_imm_buf *imm_buf = srpt_get_desc_buf(srp_cmd);
void *data = (void *)srp_cmd + imm_data_offset;
uint32_t len = be32_to_cpu(imm_buf->len);
uint32_t req_size = imm_data_offset + len;
if (req_size > srp_max_req_size) {
pr_err("Immediate data (length %d + %d) exceeds request size %d\n",
imm_data_offset, len, srp_max_req_size);
return -EINVAL;
}
if (recv_ioctx->byte_len < req_size) {
pr_err("Received too few data - %d < %d\n",
recv_ioctx->byte_len, req_size);
return -EIO;
}
/*
* The immediate data buffer descriptor must occur before the
* immediate data itself.
*/
if ((void *)(imm_buf + 1) > (void *)data) {
pr_err("Received invalid write request\n");
return -EINVAL;
}
*data_len = len;
ioctx->recv_ioctx = recv_ioctx;
if ((uintptr_t)data & 511) {
pr_warn_once("Internal error - the receive buffers are not aligned properly.\n");
return -EINVAL;
}
sg_init_one(&ioctx->imm_sg, data, len);
*sg = &ioctx->imm_sg;
*sg_cnt = 1;
return 0;
} else {
*data_len = 0;
return 0;
}
}
/**
* srpt_init_ch_qp - initialize queue pair attributes
* @ch: SRPT RDMA channel.
* @qp: Queue pair pointer.
*
* Initialized the attributes of queue pair 'qp' by allowing local write,
* remote read and remote write. Also transitions 'qp' to state IB_QPS_INIT.
*/
static int srpt_init_ch_qp(struct srpt_rdma_ch *ch, struct ib_qp *qp)
{
struct ib_qp_attr *attr;
int ret;
WARN_ON_ONCE(ch->using_rdma_cm);
attr = kzalloc(sizeof(*attr), GFP_KERNEL);
if (!attr)
return -ENOMEM;
attr->qp_state = IB_QPS_INIT;
attr->qp_access_flags = IB_ACCESS_LOCAL_WRITE;
attr->port_num = ch->sport->port;
ret = ib_find_cached_pkey(ch->sport->sdev->device, ch->sport->port,
ch->pkey, &attr->pkey_index);
if (ret < 0)
pr_err("Translating pkey %#x failed (%d) - using index 0\n",
ch->pkey, ret);
ret = ib_modify_qp(qp, attr,
IB_QP_STATE | IB_QP_ACCESS_FLAGS | IB_QP_PORT |
IB_QP_PKEY_INDEX);
kfree(attr);
return ret;
}
/**
* srpt_ch_qp_rtr - change the state of a channel to 'ready to receive' (RTR)
* @ch: channel of the queue pair.
* @qp: queue pair to change the state of.
*
* Returns zero upon success and a negative value upon failure.
*
* Note: currently a struct ib_qp_attr takes 136 bytes on a 64-bit system.
* If this structure ever becomes larger, it might be necessary to allocate
* it dynamically instead of on the stack.
*/
static int srpt_ch_qp_rtr(struct srpt_rdma_ch *ch, struct ib_qp *qp)
{
struct ib_qp_attr qp_attr;
int attr_mask;
int ret;
WARN_ON_ONCE(ch->using_rdma_cm);
qp_attr.qp_state = IB_QPS_RTR;
ret = ib_cm_init_qp_attr(ch->ib_cm.cm_id, &qp_attr, &attr_mask);
if (ret)
goto out;
qp_attr.max_dest_rd_atomic = 4;
ret = ib_modify_qp(qp, &qp_attr, attr_mask);
out:
return ret;
}
/**
* srpt_ch_qp_rts - change the state of a channel to 'ready to send' (RTS)
* @ch: channel of the queue pair.
* @qp: queue pair to change the state of.
*
* Returns zero upon success and a negative value upon failure.
*
* Note: currently a struct ib_qp_attr takes 136 bytes on a 64-bit system.
* If this structure ever becomes larger, it might be necessary to allocate
* it dynamically instead of on the stack.
*/
static int srpt_ch_qp_rts(struct srpt_rdma_ch *ch, struct ib_qp *qp)
{
struct ib_qp_attr qp_attr;
int attr_mask;
int ret;
qp_attr.qp_state = IB_QPS_RTS;
ret = ib_cm_init_qp_attr(ch->ib_cm.cm_id, &qp_attr, &attr_mask);
if (ret)
goto out;
qp_attr.max_rd_atomic = 4;
ret = ib_modify_qp(qp, &qp_attr, attr_mask);
out:
return ret;
}
/**
* srpt_ch_qp_err - set the channel queue pair state to 'error'
* @ch: SRPT RDMA channel.
*/
static int srpt_ch_qp_err(struct srpt_rdma_ch *ch)
{
struct ib_qp_attr qp_attr;
qp_attr.qp_state = IB_QPS_ERR;
return ib_modify_qp(ch->qp, &qp_attr, IB_QP_STATE);
}
/**
* srpt_get_send_ioctx - obtain an I/O context for sending to the initiator
* @ch: SRPT RDMA channel.
*/
static struct srpt_send_ioctx *srpt_get_send_ioctx(struct srpt_rdma_ch *ch)
{
struct srpt_send_ioctx *ioctx;
int tag, cpu;
BUG_ON(!ch);
tag = sbitmap_queue_get(&ch->sess->sess_tag_pool, &cpu);
if (tag < 0)
return NULL;
ioctx = ch->ioctx_ring[tag];
BUG_ON(ioctx->ch != ch);
ioctx->state = SRPT_STATE_NEW;
WARN_ON_ONCE(ioctx->recv_ioctx);
ioctx->n_rdma = 0;
ioctx->n_rw_ctx = 0;
ioctx->queue_status_only = false;
/*
* transport_init_se_cmd() does not initialize all fields, so do it
* here.
*/
memset(&ioctx->cmd, 0, sizeof(ioctx->cmd));
memset(&ioctx->sense_data, 0, sizeof(ioctx->sense_data));
ioctx->cmd.map_tag = tag;
ioctx->cmd.map_cpu = cpu;
return ioctx;
}
/**
* srpt_abort_cmd - abort a SCSI command
* @ioctx: I/O context associated with the SCSI command.
*/
static int srpt_abort_cmd(struct srpt_send_ioctx *ioctx)
{
enum srpt_command_state state;
BUG_ON(!ioctx);
/*
* If the command is in a state where the target core is waiting for
* the ib_srpt driver, change the state to the next state.
*/
state = ioctx->state;
switch (state) {
case SRPT_STATE_NEED_DATA:
ioctx->state = SRPT_STATE_DATA_IN;
break;
case SRPT_STATE_CMD_RSP_SENT:
case SRPT_STATE_MGMT_RSP_SENT:
ioctx->state = SRPT_STATE_DONE;
break;
default:
WARN_ONCE(true, "%s: unexpected I/O context state %d\n",
__func__, state);
break;
}
pr_debug("Aborting cmd with state %d -> %d and tag %lld\n", state,
ioctx->state, ioctx->cmd.tag);
switch (state) {
case SRPT_STATE_NEW:
case SRPT_STATE_DATA_IN:
case SRPT_STATE_MGMT:
case SRPT_STATE_DONE:
/*
* Do nothing - defer abort processing until
* srpt_queue_response() is invoked.
*/
break;
case SRPT_STATE_NEED_DATA:
pr_debug("tag %#llx: RDMA read error\n", ioctx->cmd.tag);
transport_generic_request_failure(&ioctx->cmd,
TCM_CHECK_CONDITION_ABORT_CMD);
break;
case SRPT_STATE_CMD_RSP_SENT:
/*
* SRP_RSP sending failed or the SRP_RSP send completion has
* not been received in time.
*/
transport_generic_free_cmd(&ioctx->cmd, 0);
break;
case SRPT_STATE_MGMT_RSP_SENT:
transport_generic_free_cmd(&ioctx->cmd, 0);
break;
default:
WARN(1, "Unexpected command state (%d)", state);
break;
}
return state;
}
/**
* srpt_rdma_read_done - RDMA read completion callback
* @cq: Completion queue.
* @wc: Work completion.
*
* XXX: what is now target_execute_cmd used to be asynchronous, and unmapping
* the data that has been transferred via IB RDMA had to be postponed until the
* check_stop_free() callback. None of this is necessary anymore and needs to
* be cleaned up.
*/
static void srpt_rdma_read_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct srpt_rdma_ch *ch = cq->cq_context;
struct srpt_send_ioctx *ioctx =
container_of(wc->wr_cqe, struct srpt_send_ioctx, rdma_cqe);
WARN_ON(ioctx->n_rdma <= 0);
atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
ioctx->n_rdma = 0;
if (unlikely(wc->status != IB_WC_SUCCESS)) {
pr_info("RDMA_READ for ioctx 0x%p failed with status %d\n",
ioctx, wc->status);
srpt_abort_cmd(ioctx);
return;
}
if (srpt_test_and_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA,
SRPT_STATE_DATA_IN))
target_execute_cmd(&ioctx->cmd);
else
pr_err("%s[%d]: wrong state = %d\n", __func__,
__LINE__, ioctx->state);
}
/**
* srpt_build_cmd_rsp - build a SRP_RSP response
* @ch: RDMA channel through which the request has been received.
* @ioctx: I/O context associated with the SRP_CMD request. The response will
* be built in the buffer ioctx->buf points at and hence this function will
* overwrite the request data.
* @tag: tag of the request for which this response is being generated.
* @status: value for the STATUS field of the SRP_RSP information unit.
*
* Returns the size in bytes of the SRP_RSP response.
*
* An SRP_RSP response contains a SCSI status or service response. See also
* section 6.9 in the SRP r16a document for the format of an SRP_RSP
* response. See also SPC-2 for more information about sense data.
*/
static int srpt_build_cmd_rsp(struct srpt_rdma_ch *ch,
struct srpt_send_ioctx *ioctx, u64 tag,
int status)
{
struct se_cmd *cmd = &ioctx->cmd;
struct srp_rsp *srp_rsp;
const u8 *sense_data;
int sense_data_len, max_sense_len;
u32 resid = cmd->residual_count;
/*
* The lowest bit of all SAM-3 status codes is zero (see also
* paragraph 5.3 in SAM-3).
*/
WARN_ON(status & 1);
srp_rsp = ioctx->ioctx.buf;
BUG_ON(!srp_rsp);
sense_data = ioctx->sense_data;
sense_data_len = ioctx->cmd.scsi_sense_length;
WARN_ON(sense_data_len > sizeof(ioctx->sense_data));
memset(srp_rsp, 0, sizeof(*srp_rsp));
srp_rsp->opcode = SRP_RSP;
srp_rsp->req_lim_delta =
cpu_to_be32(1 + atomic_xchg(&ch->req_lim_delta, 0));
srp_rsp->tag = tag;
srp_rsp->status = status;
if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
if (cmd->data_direction == DMA_TO_DEVICE) {
/* residual data from an underflow write */
srp_rsp->flags = SRP_RSP_FLAG_DOUNDER;
srp_rsp->data_out_res_cnt = cpu_to_be32(resid);
} else if (cmd->data_direction == DMA_FROM_DEVICE) {
/* residual data from an underflow read */
srp_rsp->flags = SRP_RSP_FLAG_DIUNDER;
srp_rsp->data_in_res_cnt = cpu_to_be32(resid);
}
} else if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
if (cmd->data_direction == DMA_TO_DEVICE) {
/* residual data from an overflow write */
srp_rsp->flags = SRP_RSP_FLAG_DOOVER;
srp_rsp->data_out_res_cnt = cpu_to_be32(resid);
} else if (cmd->data_direction == DMA_FROM_DEVICE) {
/* residual data from an overflow read */
srp_rsp->flags = SRP_RSP_FLAG_DIOVER;
srp_rsp->data_in_res_cnt = cpu_to_be32(resid);
}
}
if (sense_data_len) {
BUILD_BUG_ON(MIN_MAX_RSP_SIZE <= sizeof(*srp_rsp));
max_sense_len = ch->max_ti_iu_len - sizeof(*srp_rsp);
if (sense_data_len > max_sense_len) {
pr_warn("truncated sense data from %d to %d bytes\n",
sense_data_len, max_sense_len);
sense_data_len = max_sense_len;
}
srp_rsp->flags |= SRP_RSP_FLAG_SNSVALID;
srp_rsp->sense_data_len = cpu_to_be32(sense_data_len);
memcpy(srp_rsp + 1, sense_data, sense_data_len);
}
return sizeof(*srp_rsp) + sense_data_len;
}
/**
* srpt_build_tskmgmt_rsp - build a task management response
* @ch: RDMA channel through which the request has been received.
* @ioctx: I/O context in which the SRP_RSP response will be built.
* @rsp_code: RSP_CODE that will be stored in the response.
* @tag: Tag of the request for which this response is being generated.
*
* Returns the size in bytes of the SRP_RSP response.
*
* An SRP_RSP response contains a SCSI status or service response. See also
* section 6.9 in the SRP r16a document for the format of an SRP_RSP
* response.
*/
static int srpt_build_tskmgmt_rsp(struct srpt_rdma_ch *ch,
struct srpt_send_ioctx *ioctx,
u8 rsp_code, u64 tag)
{
struct srp_rsp *srp_rsp;
int resp_data_len;
int resp_len;
resp_data_len = 4;
resp_len = sizeof(*srp_rsp) + resp_data_len;
srp_rsp = ioctx->ioctx.buf;
BUG_ON(!srp_rsp);
memset(srp_rsp, 0, sizeof(*srp_rsp));
srp_rsp->opcode = SRP_RSP;
srp_rsp->req_lim_delta =
cpu_to_be32(1 + atomic_xchg(&ch->req_lim_delta, 0));
srp_rsp->tag = tag;
srp_rsp->flags |= SRP_RSP_FLAG_RSPVALID;
srp_rsp->resp_data_len = cpu_to_be32(resp_data_len);
srp_rsp->data[3] = rsp_code;
return resp_len;
}
static int srpt_check_stop_free(struct se_cmd *cmd)
{
struct srpt_send_ioctx *ioctx = container_of(cmd,
struct srpt_send_ioctx, cmd);
return target_put_sess_cmd(&ioctx->cmd);
}
/**
* srpt_handle_cmd - process a SRP_CMD information unit
* @ch: SRPT RDMA channel.
* @recv_ioctx: Receive I/O context.
* @send_ioctx: Send I/O context.
*/
static void srpt_handle_cmd(struct srpt_rdma_ch *ch,
struct srpt_recv_ioctx *recv_ioctx,
struct srpt_send_ioctx *send_ioctx)
{
struct se_cmd *cmd;
struct srp_cmd *srp_cmd;
struct scatterlist *sg = NULL;
unsigned sg_cnt = 0;
u64 data_len;
enum dma_data_direction dir;
int rc;
BUG_ON(!send_ioctx);
srp_cmd = recv_ioctx->ioctx.buf + recv_ioctx->ioctx.offset;
cmd = &send_ioctx->cmd;
cmd->tag = srp_cmd->tag;
switch (srp_cmd->task_attr) {
case SRP_CMD_SIMPLE_Q:
cmd->sam_task_attr = TCM_SIMPLE_TAG;
break;
case SRP_CMD_ORDERED_Q:
default:
cmd->sam_task_attr = TCM_ORDERED_TAG;
break;
case SRP_CMD_HEAD_OF_Q:
cmd->sam_task_attr = TCM_HEAD_TAG;
break;
case SRP_CMD_ACA:
cmd->sam_task_attr = TCM_ACA_TAG;
break;
}
rc = srpt_get_desc_tbl(recv_ioctx, send_ioctx, srp_cmd, &dir,
&sg, &sg_cnt, &data_len, ch->imm_data_offset);
if (rc) {
if (rc != -EAGAIN) {
pr_err("0x%llx: parsing SRP descriptor table failed.\n",
srp_cmd->tag);
}
goto busy;
}
rc = target_submit_cmd_map_sgls(cmd, ch->sess, srp_cmd->cdb,
&send_ioctx->sense_data[0],
scsilun_to_int(&srp_cmd->lun), data_len,
TCM_SIMPLE_TAG, dir, TARGET_SCF_ACK_KREF,
sg, sg_cnt, NULL, 0, NULL, 0);
if (rc != 0) {
pr_debug("target_submit_cmd() returned %d for tag %#llx\n", rc,
srp_cmd->tag);
goto busy;
}
return;
busy:
target_send_busy(cmd);
}
static int srp_tmr_to_tcm(int fn)
{
switch (fn) {
case SRP_TSK_ABORT_TASK:
return TMR_ABORT_TASK;
case SRP_TSK_ABORT_TASK_SET:
return TMR_ABORT_TASK_SET;
case SRP_TSK_CLEAR_TASK_SET:
return TMR_CLEAR_TASK_SET;
case SRP_TSK_LUN_RESET:
return TMR_LUN_RESET;
case SRP_TSK_CLEAR_ACA:
return TMR_CLEAR_ACA;
default:
return -1;
}
}
/**
* srpt_handle_tsk_mgmt - process a SRP_TSK_MGMT information unit
* @ch: SRPT RDMA channel.
* @recv_ioctx: Receive I/O context.
* @send_ioctx: Send I/O context.
*
* Returns 0 if and only if the request will be processed by the target core.
*
* For more information about SRP_TSK_MGMT information units, see also section
* 6.7 in the SRP r16a document.
*/
static void srpt_handle_tsk_mgmt(struct srpt_rdma_ch *ch,
struct srpt_recv_ioctx *recv_ioctx,
struct srpt_send_ioctx *send_ioctx)
{
struct srp_tsk_mgmt *srp_tsk;
struct se_cmd *cmd;
struct se_session *sess = ch->sess;
int tcm_tmr;
int rc;
BUG_ON(!send_ioctx);
srp_tsk = recv_ioctx->ioctx.buf + recv_ioctx->ioctx.offset;
cmd = &send_ioctx->cmd;
pr_debug("recv tsk_mgmt fn %d for task_tag %lld and cmd tag %lld ch %p sess %p\n",
srp_tsk->tsk_mgmt_func, srp_tsk->task_tag, srp_tsk->tag, ch,
ch->sess);
srpt_set_cmd_state(send_ioctx, SRPT_STATE_MGMT);
send_ioctx->cmd.tag = srp_tsk->tag;
tcm_tmr = srp_tmr_to_tcm(srp_tsk->tsk_mgmt_func);
rc = target_submit_tmr(&send_ioctx->cmd, sess, NULL,
scsilun_to_int(&srp_tsk->lun), srp_tsk, tcm_tmr,
GFP_KERNEL, srp_tsk->task_tag,
TARGET_SCF_ACK_KREF);
if (rc != 0) {
send_ioctx->cmd.se_tmr_req->response = TMR_FUNCTION_REJECTED;
cmd->se_tfo->queue_tm_rsp(cmd);
}
return;
}
/**
* srpt_handle_new_iu - process a newly received information unit
* @ch: RDMA channel through which the information unit has been received.
* @recv_ioctx: Receive I/O context associated with the information unit.
*/
static bool
srpt_handle_new_iu(struct srpt_rdma_ch *ch, struct srpt_recv_ioctx *recv_ioctx)
{
struct srpt_send_ioctx *send_ioctx = NULL;
struct srp_cmd *srp_cmd;
bool res = false;
u8 opcode;
BUG_ON(!ch);
BUG_ON(!recv_ioctx);
if (unlikely(ch->state == CH_CONNECTING))
goto push;
ib_dma_sync_single_for_cpu(ch->sport->sdev->device,
recv_ioctx->ioctx.dma,
recv_ioctx->ioctx.offset + srp_max_req_size,
DMA_FROM_DEVICE);
srp_cmd = recv_ioctx->ioctx.buf + recv_ioctx->ioctx.offset;
opcode = srp_cmd->opcode;
if (opcode == SRP_CMD || opcode == SRP_TSK_MGMT) {
send_ioctx = srpt_get_send_ioctx(ch);
if (unlikely(!send_ioctx))
goto push;
}
if (!list_empty(&recv_ioctx->wait_list)) {
WARN_ON_ONCE(!ch->processing_wait_list);
list_del_init(&recv_ioctx->wait_list);
}
switch (opcode) {
case SRP_CMD:
srpt_handle_cmd(ch, recv_ioctx, send_ioctx);
break;
case SRP_TSK_MGMT:
srpt_handle_tsk_mgmt(ch, recv_ioctx, send_ioctx);
break;
case SRP_I_LOGOUT:
pr_err("Not yet implemented: SRP_I_LOGOUT\n");
break;
case SRP_CRED_RSP:
pr_debug("received SRP_CRED_RSP\n");
break;
case SRP_AER_RSP:
pr_debug("received SRP_AER_RSP\n");
break;
case SRP_RSP:
pr_err("Received SRP_RSP\n");
break;
default:
pr_err("received IU with unknown opcode 0x%x\n", opcode);
break;
}
if (!send_ioctx || !send_ioctx->recv_ioctx)
srpt_post_recv(ch->sport->sdev, ch, recv_ioctx);
res = true;
out:
return res;
push:
if (list_empty(&recv_ioctx->wait_list)) {
WARN_ON_ONCE(ch->processing_wait_list);
list_add_tail(&recv_ioctx->wait_list, &ch->cmd_wait_list);
}
goto out;
}
static void srpt_recv_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct srpt_rdma_ch *ch = cq->cq_context;
struct srpt_recv_ioctx *ioctx =
container_of(wc->wr_cqe, struct srpt_recv_ioctx, ioctx.cqe);
if (wc->status == IB_WC_SUCCESS) {
int req_lim;
req_lim = atomic_dec_return(&ch->req_lim);
if (unlikely(req_lim < 0))
pr_err("req_lim = %d < 0\n", req_lim);
ioctx->byte_len = wc->byte_len;
srpt_handle_new_iu(ch, ioctx);
} else {
pr_info_ratelimited("receiving failed for ioctx %p with status %d\n",
ioctx, wc->status);
}
}
/*
* This function must be called from the context in which RDMA completions are
* processed because it accesses the wait list without protection against
* access from other threads.
*/
static void srpt_process_wait_list(struct srpt_rdma_ch *ch)
{
struct srpt_recv_ioctx *recv_ioctx, *tmp;
WARN_ON_ONCE(ch->state == CH_CONNECTING);
if (list_empty(&ch->cmd_wait_list))
return;
WARN_ON_ONCE(ch->processing_wait_list);
ch->processing_wait_list = true;
list_for_each_entry_safe(recv_ioctx, tmp, &ch->cmd_wait_list,
wait_list) {
if (!srpt_handle_new_iu(ch, recv_ioctx))
break;
}
ch->processing_wait_list = false;
}
/**
* srpt_send_done - send completion callback
* @cq: Completion queue.
* @wc: Work completion.
*
* Note: Although this has not yet been observed during tests, at least in
* theory it is possible that the srpt_get_send_ioctx() call invoked by
* srpt_handle_new_iu() fails. This is possible because the req_lim_delta
* value in each response is set to one, and it is possible that this response
* makes the initiator send a new request before the send completion for that
* response has been processed. This could e.g. happen if the call to
* srpt_put_send_iotcx() is delayed because of a higher priority interrupt or
* if IB retransmission causes generation of the send completion to be
* delayed. Incoming information units for which srpt_get_send_ioctx() fails
* are queued on cmd_wait_list. The code below processes these delayed
* requests one at a time.
*/
static void srpt_send_done(struct ib_cq *cq, struct ib_wc *wc)
{
struct srpt_rdma_ch *ch = cq->cq_context;
struct srpt_send_ioctx *ioctx =
container_of(wc->wr_cqe, struct srpt_send_ioctx, ioctx.cqe);
enum srpt_command_state state;
state = srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
WARN_ON(state != SRPT_STATE_CMD_RSP_SENT &&
state != SRPT_STATE_MGMT_RSP_SENT);
atomic_add(1 + ioctx->n_rdma, &ch->sq_wr_avail);
if (wc->status != IB_WC_SUCCESS)
pr_info("sending response for ioctx 0x%p failed with status %d\n",
ioctx, wc->status);
if (state != SRPT_STATE_DONE) {
transport_generic_free_cmd(&ioctx->cmd, 0);
} else {
pr_err("IB completion has been received too late for wr_id = %u.\n",
ioctx->ioctx.index);
}
srpt_process_wait_list(ch);
}
/**
* srpt_create_ch_ib - create receive and send completion queues
* @ch: SRPT RDMA channel.
*/
static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
{
struct ib_qp_init_attr *qp_init;
struct srpt_port *sport = ch->sport;
struct srpt_device *sdev = sport->sdev;
const struct ib_device_attr *attrs = &sdev->device->attrs;
int sq_size = sport->port_attrib.srp_sq_size;
int i, ret;
WARN_ON(ch->rq_size < 1);
ret = -ENOMEM;
qp_init = kzalloc(sizeof(*qp_init), GFP_KERNEL);
if (!qp_init)
goto out;
retry:
ch->cq = ib_alloc_cq_any(sdev->device, ch, ch->rq_size + sq_size,
IB_POLL_WORKQUEUE);
if (IS_ERR(ch->cq)) {
ret = PTR_ERR(ch->cq);
pr_err("failed to create CQ cqe= %d ret= %d\n",
ch->rq_size + sq_size, ret);
goto out;
}
qp_init->qp_context = (void *)ch;
qp_init->event_handler
= (void(*)(struct ib_event *, void*))srpt_qp_event;
qp_init->send_cq = ch->cq;
qp_init->recv_cq = ch->cq;
qp_init->sq_sig_type = IB_SIGNAL_REQ_WR;
qp_init->qp_type = IB_QPT_RC;
/*
* We divide up our send queue size into half SEND WRs to send the
* completions, and half R/W contexts to actually do the RDMA
* READ/WRITE transfers. Note that we need to allocate CQ slots for
* both both, as RDMA contexts will also post completions for the
* RDMA READ case.
*/
qp_init->cap.max_send_wr = min(sq_size / 2, attrs->max_qp_wr);
qp_init->cap.max_rdma_ctxs = sq_size / 2;
qp_init->cap.max_send_sge = min(attrs->max_send_sge,
SRPT_MAX_SG_PER_WQE);
qp_init->cap.max_recv_sge = min(attrs->max_recv_sge,
SRPT_MAX_SG_PER_WQE);
qp_init->port_num = ch->sport->port;
if (sdev->use_srq) {
qp_init->srq = sdev->srq;
} else {
qp_init->cap.max_recv_wr = ch->rq_size;
qp_init->cap.max_recv_sge = min(attrs->max_recv_sge,
SRPT_MAX_SG_PER_WQE);
}
if (ch->using_rdma_cm) {
ret = rdma_create_qp(ch->rdma_cm.cm_id, sdev->pd, qp_init);
ch->qp = ch->rdma_cm.cm_id->qp;
} else {
ch->qp = ib_create_qp(sdev->pd, qp_init);
if (!IS_ERR(ch->qp)) {
ret = srpt_init_ch_qp(ch, ch->qp);
if (ret)
ib_destroy_qp(ch->qp);
} else {
ret = PTR_ERR(ch->qp);
}
}
if (ret) {
bool retry = sq_size > MIN_SRPT_SQ_SIZE;
if (retry) {
pr_debug("failed to create queue pair with sq_size = %d (%d) - retrying\n",
sq_size, ret);
ib_free_cq(ch->cq);
sq_size = max(sq_size / 2, MIN_SRPT_SQ_SIZE);
goto retry;
} else {
pr_err("failed to create queue pair with sq_size = %d (%d)\n",
sq_size, ret);
goto err_destroy_cq;
}
}
atomic_set(&ch->sq_wr_avail, qp_init->cap.max_send_wr);
pr_debug("%s: max_cqe= %d max_sge= %d sq_size = %d ch= %p\n",
__func__, ch->cq->cqe, qp_init->cap.max_send_sge,
qp_init->cap.max_send_wr, ch);
if (!sdev->use_srq)
for (i = 0; i < ch->rq_size; i++)
srpt_post_recv(sdev, ch, ch->ioctx_recv_ring[i]);
out:
kfree(qp_init);
return ret;
err_destroy_cq:
ch->qp = NULL;
ib_free_cq(ch->cq);
goto out;
}
static void srpt_destroy_ch_ib(struct srpt_rdma_ch *ch)
{
ib_destroy_qp(ch->qp);
ib_free_cq(ch->cq);
}
/**
* srpt_close_ch - close a RDMA channel
* @ch: SRPT RDMA channel.
*
* Make sure all resources associated with the channel will be deallocated at
* an appropriate time.
*
* Returns true if and only if the channel state has been modified into
* CH_DRAINING.
*/
static bool srpt_close_ch(struct srpt_rdma_ch *ch)
{
int ret;
if (!srpt_set_ch_state(ch, CH_DRAINING)) {
pr_debug("%s: already closed\n", ch->sess_name);
return false;
}
kref_get(&ch->kref);
ret = srpt_ch_qp_err(ch);
if (ret < 0)
pr_err("%s-%d: changing queue pair into error state failed: %d\n",
ch->sess_name, ch->qp->qp_num, ret);
ret = srpt_zerolength_write(ch);
if (ret < 0) {
pr_err("%s-%d: queuing zero-length write failed: %d\n",
ch->sess_name, ch->qp->qp_num, ret);
if (srpt_set_ch_state(ch, CH_DISCONNECTED))
schedule_work(&ch->release_work);
else
WARN_ON_ONCE(true);
}
kref_put(&ch->kref, srpt_free_ch);
return true;
}
/*
* Change the channel state into CH_DISCONNECTING. If a channel has not yet
* reached the connected state, close it. If a channel is in the connected
* state, send a DREQ. If a DREQ has been received, send a DREP. Note: it is
* the responsibility of the caller to ensure that this function is not
* invoked concurrently with the code that accepts a connection. This means
* that this function must either be invoked from inside a CM callback
* function or that it must be invoked with the srpt_port.mutex held.
*/
static int srpt_disconnect_ch(struct srpt_rdma_ch *ch)
{
int ret;
if (!srpt_set_ch_state(ch, CH_DISCONNECTING))
return -ENOTCONN;
if (ch->using_rdma_cm) {
ret = rdma_disconnect(ch->rdma_cm.cm_id);
} else {
ret = ib_send_cm_dreq(ch->ib_cm.cm_id, NULL, 0);
if (ret < 0)
ret = ib_send_cm_drep(ch->ib_cm.cm_id, NULL, 0);
}
if (ret < 0 && srpt_close_ch(ch))
ret = 0;
return ret;
}
/* Send DREQ and wait for DREP. */
static void srpt_disconnect_ch_sync(struct srpt_rdma_ch *ch)
{
DECLARE_COMPLETION_ONSTACK(closed);
struct srpt_port *sport = ch->sport;
pr_debug("ch %s-%d state %d\n", ch->sess_name, ch->qp->qp_num,
ch->state);
ch->closed = &closed;
mutex_lock(&sport->mutex);
srpt_disconnect_ch(ch);
mutex_unlock(&sport->mutex);
while (wait_for_completion_timeout(&closed, 5 * HZ) == 0)
pr_info("%s(%s-%d state %d): still waiting ...\n", __func__,
ch->sess_name, ch->qp->qp_num, ch->state);
}
static void __srpt_close_all_ch(struct srpt_port *sport)
{
struct srpt_nexus *nexus;
struct srpt_rdma_ch *ch;
lockdep_assert_held(&sport->mutex);
list_for_each_entry(nexus, &sport->nexus_list, entry) {
list_for_each_entry(ch, &nexus->ch_list, list) {
if (srpt_disconnect_ch(ch) >= 0)
pr_info("Closing channel %s because target %s_%d has been disabled\n",
ch->sess_name,
dev_name(&sport->sdev->device->dev),
sport->port);
srpt_close_ch(ch);
}
}
}
/*
* Look up (i_port_id, t_port_id) in sport->nexus_list. Create an entry if
* it does not yet exist.
*/
static struct srpt_nexus *srpt_get_nexus(struct srpt_port *sport,
const u8 i_port_id[16],
const u8 t_port_id[16])
{
struct srpt_nexus *nexus = NULL, *tmp_nexus = NULL, *n;
for (;;) {
mutex_lock(&sport->mutex);
list_for_each_entry(n, &sport->nexus_list, entry) {
if (memcmp(n->i_port_id, i_port_id, 16) == 0 &&
memcmp(n->t_port_id, t_port_id, 16) == 0) {
nexus = n;
break;
}
}
if (!nexus && tmp_nexus) {
list_add_tail_rcu(&tmp_nexus->entry,
&sport->nexus_list);
swap(nexus, tmp_nexus);
}
mutex_unlock(&sport->mutex);
if (nexus)
break;
tmp_nexus = kzalloc(sizeof(*nexus), GFP_KERNEL);
if (!tmp_nexus) {
nexus = ERR_PTR(-ENOMEM);
break;
}
INIT_LIST_HEAD(&tmp_nexus->ch_list);
memcpy(tmp_nexus->i_port_id, i_port_id, 16);
memcpy(tmp_nexus->t_port_id, t_port_id, 16);
}
kfree(tmp_nexus);
return nexus;
}
static void srpt_set_enabled(struct srpt_port *sport, bool enabled)
__must_hold(&sport->mutex)
{
lockdep_assert_held(&sport->mutex);
if (sport->enabled == enabled)
return;
sport->enabled = enabled;
if (!enabled)
__srpt_close_all_ch(sport);
}
static void srpt_drop_sport_ref(struct srpt_port *sport)
{
if (atomic_dec_return(&sport->refcount) == 0 && sport->freed_channels)
complete(sport->freed_channels);
}
static void srpt_free_ch(struct kref *kref)
{
struct srpt_rdma_ch *ch = container_of(kref, struct srpt_rdma_ch, kref);
srpt_drop_sport_ref(ch->sport);
kfree_rcu(ch, rcu);
}
/*
* Shut down the SCSI target session, tell the connection manager to
* disconnect the associated RDMA channel, transition the QP to the error
* state and remove the channel from the channel list. This function is
* typically called from inside srpt_zerolength_write_done(). Concurrent
* srpt_zerolength_write() calls from inside srpt_close_ch() are possible
* as long as the channel is on sport->nexus_list.
*/
static void srpt_release_channel_work(struct work_struct *w)
{
struct srpt_rdma_ch *ch;
struct srpt_device *sdev;
struct srpt_port *sport;
struct se_session *se_sess;
ch = container_of(w, struct srpt_rdma_ch, release_work);
pr_debug("%s-%d\n", ch->sess_name, ch->qp->qp_num);
sdev = ch->sport->sdev;
BUG_ON(!sdev);
se_sess = ch->sess;
BUG_ON(!se_sess);
target_sess_cmd_list_set_waiting(se_sess);
target_wait_for_sess_cmds(se_sess);
target_remove_session(se_sess);
ch->sess = NULL;
if (ch->using_rdma_cm)
rdma_destroy_id(ch->rdma_cm.cm_id);
else
ib_destroy_cm_id(ch->ib_cm.cm_id);
sport = ch->sport;
mutex_lock(&sport->mutex);
list_del_rcu(&ch->list);
mutex_unlock(&sport->mutex);
if (ch->closed)
complete(ch->closed);
srpt_destroy_ch_ib(ch);
srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
ch->sport->sdev, ch->rq_size,
ch->rsp_buf_cache, DMA_TO_DEVICE);
kmem_cache_destroy(ch->rsp_buf_cache);
srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_recv_ring,
sdev, ch->rq_size,
ch->req_buf_cache, DMA_FROM_DEVICE);
kmem_cache_destroy(ch->req_buf_cache);
kref_put(&ch->kref, srpt_free_ch);
}
/**
* srpt_cm_req_recv - process the event IB_CM_REQ_RECEIVED
* @sdev: HCA through which the login request was received.
* @ib_cm_id: IB/CM connection identifier in case of IB/CM.
* @rdma_cm_id: RDMA/CM connection identifier in case of RDMA/CM.
* @port_num: Port through which the REQ message was received.
* @pkey: P_Key of the incoming connection.
* @req: SRP login request.
* @src_addr: GID (IB/CM) or IP address (RDMA/CM) of the port that submitted
* the login request.
*
* Ownership of the cm_id is transferred to the target session if this
* function returns zero. Otherwise the caller remains the owner of cm_id.
*/
static int srpt_cm_req_recv(struct srpt_device *const sdev,
struct ib_cm_id *ib_cm_id,
struct rdma_cm_id *rdma_cm_id,
u8 port_num, __be16 pkey,
const struct srp_login_req *req,
const char *src_addr)
{
struct srpt_port *sport = &sdev->port[port_num - 1];
struct srpt_nexus *nexus;
struct srp_login_rsp *rsp = NULL;
struct srp_login_rej *rej = NULL;
union {
struct rdma_conn_param rdma_cm;
struct ib_cm_rep_param ib_cm;
} *rep_param = NULL;
struct srpt_rdma_ch *ch = NULL;
char i_port_id[36];
u32 it_iu_len;
int i, tag_num, tag_size, ret;
struct srpt_tpg *stpg;
WARN_ON_ONCE(irqs_disabled());
if (WARN_ON(!sdev || !req))
return -EINVAL;
it_iu_len = be32_to_cpu(req->req_it_iu_len);
pr_info("Received SRP_LOGIN_REQ with i_port_id %pI6, t_port_id %pI6 and it_iu_len %d on port %d (guid=%pI6); pkey %#04x\n",
req->initiator_port_id, req->target_port_id, it_iu_len,
port_num, &sport->gid, be16_to_cpu(pkey));
nexus = srpt_get_nexus(sport, req->initiator_port_id,
req->target_port_id);
if (IS_ERR(nexus)) {
ret = PTR_ERR(nexus);
goto out;
}
ret = -ENOMEM;
rsp = kzalloc(sizeof(*rsp), GFP_KERNEL);
rej = kzalloc(sizeof(*rej), GFP_KERNEL);
rep_param = kzalloc(sizeof(*rep_param), GFP_KERNEL);
if (!rsp || !rej || !rep_param)
goto out;
ret = -EINVAL;
if (it_iu_len > srp_max_req_size || it_iu_len < 64) {
rej->reason = cpu_to_be32(
SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE);
pr_err("rejected SRP_LOGIN_REQ because its length (%d bytes) is out of range (%d .. %d)\n",
it_iu_len, 64, srp_max_req_size);
goto reject;
}
if (!sport->enabled) {
rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
pr_info("rejected SRP_LOGIN_REQ because target port %s_%d has not yet been enabled\n",
dev_name(&sport->sdev->device->dev), port_num);
goto reject;
}
if (*(__be64 *)req->target_port_id != cpu_to_be64(srpt_service_guid)
|| *(__be64 *)(req->target_port_id + 8) !=
cpu_to_be64(srpt_service_guid)) {
rej->reason = cpu_to_be32(
SRP_LOGIN_REJ_UNABLE_ASSOCIATE_CHANNEL);
pr_err("rejected SRP_LOGIN_REQ because it has an invalid target port identifier.\n");
goto reject;
}
ret = -ENOMEM;
ch = kzalloc(sizeof(*ch), GFP_KERNEL);
if (!ch) {
rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
pr_err("rejected SRP_LOGIN_REQ because out of memory.\n");
goto reject;
}
kref_init(&ch->kref);
ch->pkey = be16_to_cpu(pkey);
ch->nexus = nexus;
ch->zw_cqe.done = srpt_zerolength_write_done;
INIT_WORK(&ch->release_work, srpt_release_channel_work);
ch->sport = sport;
if (ib_cm_id) {
ch->ib_cm.cm_id = ib_cm_id;
ib_cm_id->context = ch;
} else {
ch->using_rdma_cm = true;
ch->rdma_cm.cm_id = rdma_cm_id;
rdma_cm_id->context = ch;
}
/*
* ch->rq_size should be at least as large as the initiator queue
* depth to avoid that the initiator driver has to report QUEUE_FULL
* to the SCSI mid-layer.
*/
ch->rq_size = min(MAX_SRPT_RQ_SIZE, sdev->device->attrs.max_qp_wr);
spin_lock_init(&ch->spinlock);
ch->state = CH_CONNECTING;
INIT_LIST_HEAD(&ch->cmd_wait_list);
ch->max_rsp_size = ch->sport->port_attrib.srp_max_rsp_size;
ch->rsp_buf_cache = kmem_cache_create("srpt-rsp-buf", ch->max_rsp_size,
512, 0, NULL);
if (!ch->rsp_buf_cache)
goto free_ch;
ch->ioctx_ring = (struct srpt_send_ioctx **)
srpt_alloc_ioctx_ring(ch->sport->sdev, ch->rq_size,
sizeof(*ch->ioctx_ring[0]),
ch->rsp_buf_cache, 0, DMA_TO_DEVICE);
if (!ch->ioctx_ring) {
pr_err("rejected SRP_LOGIN_REQ because creating a new QP SQ ring failed.\n");
rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
goto free_rsp_cache;
}
for (i = 0; i < ch->rq_size; i++)
ch->ioctx_ring[i]->ch = ch;
if (!sdev->use_srq) {
u16 imm_data_offset = req->req_flags & SRP_IMMED_REQUESTED ?
be16_to_cpu(req->imm_data_offset) : 0;
u16 alignment_offset;
u32 req_sz;
if (req->req_flags & SRP_IMMED_REQUESTED)
pr_debug("imm_data_offset = %d\n",
be16_to_cpu(req->imm_data_offset));
if (imm_data_offset >= sizeof(struct srp_cmd)) {
ch->imm_data_offset = imm_data_offset;
rsp->rsp_flags |= SRP_LOGIN_RSP_IMMED_SUPP;
} else {
ch->imm_data_offset = 0;
}
alignment_offset = round_up(imm_data_offset, 512) -
imm_data_offset;
req_sz = alignment_offset + imm_data_offset + srp_max_req_size;
ch->req_buf_cache = kmem_cache_create("srpt-req-buf", req_sz,
512, 0, NULL);
if (!ch->req_buf_cache)
goto free_rsp_ring;
ch->ioctx_recv_ring = (struct srpt_recv_ioctx **)
srpt_alloc_ioctx_ring(ch->sport->sdev, ch->rq_size,
sizeof(*ch->ioctx_recv_ring[0]),
ch->req_buf_cache,
alignment_offset,
DMA_FROM_DEVICE);
if (!ch->ioctx_recv_ring) {
pr_err("rejected SRP_LOGIN_REQ because creating a new QP RQ ring failed.\n");
rej->reason =
cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
goto free_recv_cache;
}
for (i = 0; i < ch->rq_size; i++)
INIT_LIST_HEAD(&ch->ioctx_recv_ring[i]->wait_list);
}
ret = srpt_create_ch_ib(ch);
if (ret) {
rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
pr_err("rejected SRP_LOGIN_REQ because creating a new RDMA channel failed.\n");
goto free_recv_ring;
}
strlcpy(ch->sess_name, src_addr, sizeof(ch->sess_name));
snprintf(i_port_id, sizeof(i_port_id), "0x%016llx%016llx",
be64_to_cpu(*(__be64 *)nexus->i_port_id),
be64_to_cpu(*(__be64 *)(nexus->i_port_id + 8)));
pr_debug("registering src addr %s or i_port_id %s\n", ch->sess_name,
i_port_id);
tag_num = ch->rq_size;
tag_size = 1; /* ib_srpt does not use se_sess->sess_cmd_map */
mutex_lock(&sport->port_guid_id.mutex);
list_for_each_entry(stpg, &sport->port_guid_id.tpg_list, entry) {
if (!IS_ERR_OR_NULL(ch->sess))
break;
ch->sess = target_setup_session(&stpg->tpg, tag_num,
tag_size, TARGET_PROT_NORMAL,
ch->sess_name, ch, NULL);
}
mutex_unlock(&sport->port_guid_id.mutex);
mutex_lock(&sport->port_gid_id.mutex);
list_for_each_entry(stpg, &sport->port_gid_id.tpg_list, entry) {
if (!IS_ERR_OR_NULL(ch->sess))
break;
ch->sess = target_setup_session(&stpg->tpg, tag_num,
tag_size, TARGET_PROT_NORMAL, i_port_id,
ch, NULL);
if (!IS_ERR_OR_NULL(ch->sess))
break;
/* Retry without leading "0x" */
ch->sess = target_setup_session(&stpg->tpg, tag_num,
tag_size, TARGET_PROT_NORMAL,
i_port_id + 2, ch, NULL);
}
mutex_unlock(&sport->port_gid_id.mutex);
if (IS_ERR_OR_NULL(ch->sess)) {
WARN_ON_ONCE(ch->sess == NULL);
ret = PTR_ERR(ch->sess);
ch->sess = NULL;
pr_info("Rejected login for initiator %s: ret = %d.\n",
ch->sess_name, ret);
rej->reason = cpu_to_be32(ret == -ENOMEM ?
SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES :
SRP_LOGIN_REJ_CHANNEL_LIMIT_REACHED);
goto destroy_ib;
}
/*
* Once a session has been created destruction of srpt_rdma_ch objects
* will decrement sport->refcount. Hence increment sport->refcount now.
*/
atomic_inc(&sport->refcount);
mutex_lock(&sport->mutex);
if ((req->req_flags & SRP_MTCH_ACTION) == SRP_MULTICHAN_SINGLE) {
struct srpt_rdma_ch *ch2;
list_for_each_entry(ch2, &nexus->ch_list, list) {
if (srpt_disconnect_ch(ch2) < 0)
continue;
pr_info("Relogin - closed existing channel %s\n",
ch2->sess_name);
rsp->rsp_flags |= SRP_LOGIN_RSP_MULTICHAN_TERMINATED;
}
} else {
rsp->rsp_flags |= SRP_LOGIN_RSP_MULTICHAN_MAINTAINED;
}
list_add_tail_rcu(&ch->list, &nexus->ch_list);
if (!sport->enabled) {
rej->reason = cpu_to_be32(
SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
pr_info("rejected SRP_LOGIN_REQ because target %s_%d is not enabled\n",
dev_name(&sdev->device->dev), port_num);
mutex_unlock(&sport->mutex);
goto reject;
}
mutex_unlock(&sport->mutex);
ret = ch->using_rdma_cm ? 0 : srpt_ch_qp_rtr(ch, ch->qp);
if (ret) {
rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
pr_err("rejected SRP_LOGIN_REQ because enabling RTR failed (error code = %d)\n",
ret);
goto reject;
}
pr_debug("Establish connection sess=%p name=%s ch=%p\n", ch->sess,
ch->sess_name, ch);
/* create srp_login_response */
rsp->opcode = SRP_LOGIN_RSP;
rsp->tag = req->tag;
rsp->max_it_iu_len = cpu_to_be32(srp_max_req_size);
rsp->max_ti_iu_len = req->req_it_iu_len;
ch->max_ti_iu_len = it_iu_len;
rsp->buf_fmt = cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
SRP_BUF_FORMAT_INDIRECT);
rsp->req_lim_delta = cpu_to_be32(ch->rq_size);
atomic_set(&ch->req_lim, ch->rq_size);
atomic_set(&ch->req_lim_delta, 0);
/* create cm reply */
if (ch->using_rdma_cm) {
rep_param->rdma_cm.private_data = (void *)rsp;
rep_param->rdma_cm.private_data_len = sizeof(*rsp);
rep_param->rdma_cm.rnr_retry_count = 7;
rep_param->rdma_cm.flow_control = 1;
rep_param->rdma_cm.responder_resources = 4;
rep_param->rdma_cm.initiator_depth = 4;
} else {
rep_param->ib_cm.qp_num = ch->qp->qp_num;
rep_param->ib_cm.private_data = (void *)rsp;
rep_param->ib_cm.private_data_len = sizeof(*rsp);
rep_param->ib_cm.rnr_retry_count = 7;
rep_param->ib_cm.flow_control = 1;
rep_param->ib_cm.failover_accepted = 0;
rep_param->ib_cm.srq = 1;
rep_param->ib_cm.responder_resources = 4;
rep_param->ib_cm.initiator_depth = 4;
}
/*
* Hold the sport mutex while accepting a connection to avoid that
* srpt_disconnect_ch() is invoked concurrently with this code.
*/
mutex_lock(&sport->mutex);
if (sport->enabled && ch->state == CH_CONNECTING) {
if (ch->using_rdma_cm)
ret = rdma_accept(rdma_cm_id, &rep_param->rdma_cm);
else
ret = ib_send_cm_rep(ib_cm_id, &rep_param->ib_cm);
} else {
ret = -EINVAL;
}
mutex_unlock(&sport->mutex);
switch (ret) {
case 0:
break;
case -EINVAL:
goto reject;
default:
rej->reason = cpu_to_be32(SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
pr_err("sending SRP_LOGIN_REQ response failed (error code = %d)\n",
ret);
goto reject;
}
goto out;
destroy_ib:
srpt_destroy_ch_ib(ch);
free_recv_ring:
srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_recv_ring,
ch->sport->sdev, ch->rq_size,
ch->req_buf_cache, DMA_FROM_DEVICE);
free_recv_cache:
kmem_cache_destroy(ch->req_buf_cache);
free_rsp_ring:
srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
ch->sport->sdev, ch->rq_size,
ch->rsp_buf_cache, DMA_TO_DEVICE);
free_rsp_cache:
kmem_cache_destroy(ch->rsp_buf_cache);
free_ch:
if (rdma_cm_id)
rdma_cm_id->context = NULL;
else
ib_cm_id->context = NULL;
kfree(ch);
ch = NULL;
WARN_ON_ONCE(ret == 0);
reject:
pr_info("Rejecting login with reason %#x\n", be32_to_cpu(rej->reason));
rej->opcode = SRP_LOGIN_REJ;
rej->tag = req->tag;
rej->buf_fmt = cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
SRP_BUF_FORMAT_INDIRECT);
if (rdma_cm_id)
rdma_reject(rdma_cm_id, rej, sizeof(*rej));
else
ib_send_cm_rej(ib_cm_id, IB_CM_REJ_CONSUMER_DEFINED, NULL, 0,
rej, sizeof(*rej));
if (ch && ch->sess) {
srpt_close_ch(ch);
/*
* Tell the caller not to free cm_id since
* srpt_release_channel_work() will do that.
*/
ret = 0;
}
out:
kfree(rep_param);
kfree(rsp);
kfree(rej);
return ret;
}
static int srpt_ib_cm_req_recv(struct ib_cm_id *cm_id,
const struct ib_cm_req_event_param *param,
void *private_data)
{
char sguid[40];
srpt_format_guid(sguid, sizeof(sguid),
&param->primary_path->dgid.global.interface_id);
return srpt_cm_req_recv(cm_id->context, cm_id, NULL, param->port,
param->primary_path->pkey,
private_data, sguid);
}
static int srpt_rdma_cm_req_recv(struct rdma_cm_id *cm_id,
struct rdma_cm_event *event)
{
struct srpt_device *sdev;
struct srp_login_req req;
const struct srp_login_req_rdma *req_rdma;
struct sa_path_rec *path_rec = cm_id->route.path_rec;
char src_addr[40];
sdev = ib_get_client_data(cm_id->device, &srpt_client);
if (!sdev)
return -ECONNREFUSED;
if (event->param.conn.private_data_len < sizeof(*req_rdma))
return -EINVAL;
/* Transform srp_login_req_rdma into srp_login_req. */
req_rdma = event->param.conn.private_data;
memset(&req, 0, sizeof(req));
req.opcode = req_rdma->opcode;
req.tag = req_rdma->tag;
req.req_it_iu_len = req_rdma->req_it_iu_len;
req.req_buf_fmt = req_rdma->req_buf_fmt;
req.req_flags = req_rdma->req_flags;
memcpy(req.initiator_port_id, req_rdma->initiator_port_id, 16);
memcpy(req.target_port_id, req_rdma->target_port_id, 16);
req.imm_data_offset = req_rdma->imm_data_offset;
snprintf(src_addr, sizeof(src_addr), "%pIS",
&cm_id->route.addr.src_addr);
return srpt_cm_req_recv(sdev, NULL, cm_id, cm_id->port_num,
path_rec ? path_rec->pkey : 0, &req, src_addr);
}
static void srpt_cm_rej_recv(struct srpt_rdma_ch *ch,
enum ib_cm_rej_reason reason,
const u8 *private_data,
u8 private_data_len)
{
char *priv = NULL;
int i;
if (private_data_len && (priv = kmalloc(private_data_len * 3 + 1,
GFP_KERNEL))) {
for (i = 0; i < private_data_len; i++)
sprintf(priv + 3 * i, " %02x", private_data[i]);
}
pr_info("Received CM REJ for ch %s-%d; reason %d%s%s.\n",
ch->sess_name, ch->qp->qp_num, reason, private_data_len ?
"; private data" : "", priv ? priv : " (?)");
kfree(priv);
}
/**
* srpt_cm_rtu_recv - process an IB_CM_RTU_RECEIVED or USER_ESTABLISHED event
* @ch: SRPT RDMA channel.
*
* An RTU (ready to use) message indicates that the connection has been
* established and that the recipient may begin transmitting.
*/
static void srpt_cm_rtu_recv(struct srpt_rdma_ch *ch)
{
int ret;
ret = ch->using_rdma_cm ? 0 : srpt_ch_qp_rts(ch, ch->qp);
if (ret < 0) {
pr_err("%s-%d: QP transition to RTS failed\n", ch->sess_name,
ch->qp->qp_num);
srpt_close_ch(ch);
return;
}
/*
* Note: calling srpt_close_ch() if the transition to the LIVE state
* fails is not necessary since that means that that function has
* already been invoked from another thread.
*/
if (!srpt_set_ch_state(ch, CH_LIVE)) {
pr_err("%s-%d: channel transition to LIVE state failed\n",
ch->sess_name, ch->qp->qp_num);
return;
}
/* Trigger wait list processing. */
ret = srpt_zerolength_write(ch);
WARN_ONCE(ret < 0, "%d\n", ret);
}
/**
* srpt_cm_handler - IB connection manager callback function
* @cm_id: IB/CM connection identifier.
* @event: IB/CM event.
*
* A non-zero return value will cause the caller destroy the CM ID.
*
* Note: srpt_cm_handler() must only return a non-zero value when transferring
* ownership of the cm_id to a channel by srpt_cm_req_recv() failed. Returning
* a non-zero value in any other case will trigger a race with the
* ib_destroy_cm_id() call in srpt_release_channel().
*/
static int srpt_cm_handler(struct ib_cm_id *cm_id,
const struct ib_cm_event *event)
{
struct srpt_rdma_ch *ch = cm_id->context;
int ret;
ret = 0;
switch (event->event) {
case IB_CM_REQ_RECEIVED:
ret = srpt_ib_cm_req_recv(cm_id, &event->param.req_rcvd,
event->private_data);
break;
case IB_CM_REJ_RECEIVED:
srpt_cm_rej_recv(ch, event->param.rej_rcvd.reason,
event->private_data,
IB_CM_REJ_PRIVATE_DATA_SIZE);
break;
case IB_CM_RTU_RECEIVED:
case IB_CM_USER_ESTABLISHED:
srpt_cm_rtu_recv(ch);
break;
case IB_CM_DREQ_RECEIVED:
srpt_disconnect_ch(ch);
break;
case IB_CM_DREP_RECEIVED:
pr_info("Received CM DREP message for ch %s-%d.\n",
ch->sess_name, ch->qp->qp_num);
srpt_close_ch(ch);
break;
case IB_CM_TIMEWAIT_EXIT:
pr_info("Received CM TimeWait exit for ch %s-%d.\n",
ch->sess_name, ch->qp->qp_num);
srpt_close_ch(ch);
break;
case IB_CM_REP_ERROR:
pr_info("Received CM REP error for ch %s-%d.\n", ch->sess_name,
ch->qp->qp_num);
break;
case IB_CM_DREQ_ERROR:
pr_info("Received CM DREQ ERROR event.\n");
break;
case IB_CM_MRA_RECEIVED:
pr_info("Received CM MRA event\n");
break;
default:
pr_err("received unrecognized CM event %d\n", event->event);
break;
}
return ret;
}
static int srpt_rdma_cm_handler(struct rdma_cm_id *cm_id,
struct rdma_cm_event *event)
{
struct srpt_rdma_ch *ch = cm_id->context;
int ret = 0;
switch (event->event) {
case RDMA_CM_EVENT_CONNECT_REQUEST:
ret = srpt_rdma_cm_req_recv(cm_id, event);
break;
case RDMA_CM_EVENT_REJECTED:
srpt_cm_rej_recv(ch, event->status,
event->param.conn.private_data,
event->param.conn.private_data_len);
break;
case RDMA_CM_EVENT_ESTABLISHED:
srpt_cm_rtu_recv(ch);
break;
case RDMA_CM_EVENT_DISCONNECTED:
if (ch->state < CH_DISCONNECTING)
srpt_disconnect_ch(ch);
else
srpt_close_ch(ch);
break;
case RDMA_CM_EVENT_TIMEWAIT_EXIT:
srpt_close_ch(ch);
break;
case RDMA_CM_EVENT_UNREACHABLE:
pr_info("Received CM REP error for ch %s-%d.\n", ch->sess_name,
ch->qp->qp_num);
break;
case RDMA_CM_EVENT_DEVICE_REMOVAL:
case RDMA_CM_EVENT_ADDR_CHANGE:
break;
default:
pr_err("received unrecognized RDMA CM event %d\n",
event->event);
break;
}
return ret;
}
/*
* srpt_write_pending - Start data transfer from initiator to target (write).
*/
static int srpt_write_pending(struct se_cmd *se_cmd)
{
struct srpt_send_ioctx *ioctx =
container_of(se_cmd, struct srpt_send_ioctx, cmd);
struct srpt_rdma_ch *ch = ioctx->ch;
struct ib_send_wr *first_wr = NULL;
struct ib_cqe *cqe = &ioctx->rdma_cqe;
enum srpt_command_state new_state;
int ret, i;
if (ioctx->recv_ioctx) {
srpt_set_cmd_state(ioctx, SRPT_STATE_DATA_IN);
target_execute_cmd(&ioctx->cmd);
return 0;
}
new_state = srpt_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA);
WARN_ON(new_state == SRPT_STATE_DONE);
if (atomic_sub_return(ioctx->n_rdma, &ch->sq_wr_avail) < 0) {
pr_warn("%s: IB send queue full (needed %d)\n",
__func__, ioctx->n_rdma);
ret = -ENOMEM;
goto out_undo;
}
cqe->done = srpt_rdma_read_done;
for (i = ioctx->n_rw_ctx - 1; i >= 0; i--) {
struct srpt_rw_ctx *ctx = &ioctx->rw_ctxs[i];
first_wr = rdma_rw_ctx_wrs(&ctx->rw, ch->qp, ch->sport->port,
cqe, first_wr);
cqe = NULL;
}
ret = ib_post_send(ch->qp, first_wr, NULL);
if (ret) {
pr_err("%s: ib_post_send() returned %d for %d (avail: %d)\n",
__func__, ret, ioctx->n_rdma,
atomic_read(&ch->sq_wr_avail));
goto out_undo;
}
return 0;
out_undo: