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Message-ID: <4CA65983.3040102@vlnb.net>
Date: Sat, 02 Oct 2010 01:58:27 +0400
From: Vladislav Bolkhovitin <vst@...b.net>
To: linux-scsi@...r.kernel.org
CC: linux-kernel@...r.kernel.org,
scst-devel <scst-devel@...ts.sourceforge.net>,
James Bottomley <James.Bottomley@...senPartnership.com>,
Andrew Morton <akpm@...ux-foundation.org>,
FUJITA Tomonori <fujita.tomonori@....ntt.co.jp>,
Mike Christie <michaelc@...wisc.edu>,
Vu Pham <vuhuong@...lanox.com>,
Bart Van Assche <bart.vanassche@...il.com>,
James Smart <James.Smart@...lex.Com>,
Joe Eykholt <jeykholt@...co.com>, Andy Yan <ayan@...vell.com>,
Chetan Loke <generationgnu@...oo.com>,
Dmitry Torokhov <dmitry.torokhov@...il.com>,
Hannes Reinecke <hare@...e.de>,
Richard Sharpe <realrichardsharpe@...il.com>
Subject: [PATCH 17/19]: SCST InfiniBand SRP target driver
This patch contains SCST InfiniBand SRP target driver.
This driver works directly on top of InfiniBand stack and SCST.
It is a high performance driver capable of handling 600K+ 4K random write
IOPS by a single target as well as 2.5+GB/s sequential throughput from
a single QDR IB port.
It was originally developed by Vu Pham/Mellanox, currently
Bart Van Assche is maintaining and improving it.
Signed-off-by: Vu Pham <vu@...lanox.com>
Signed-off-by: Bart Van Assche <bart.vanassche@...il.com>
Signed-off-by: Vladislav Bolkhovitin <vst@...b.net>
---
Documentation/scst/README.srpt | 112 +
drivers/scst/srpt/Kconfig | 12
drivers/scst/srpt/Makefile | 1
drivers/scst/srpt/ib_dm_mad.h | 139 +
drivers/scst/srpt/ib_srpt.c | 3809 +++++++++++++++++++++++++++++++++++++++++
drivers/scst/srpt/ib_srpt.h | 370 +++
6 files changed, 4443 insertions(+)
diff -uprN orig/linux-2.6.35/drivers/scst/srpt/Kconfig linux-2.6.35/drivers/scst/srpt/Kconfig
--- orig/linux-2.6.35/drivers/scst/srpt/Kconfig
+++ linux-2.6.35/drivers/scst/srpt/Kconfig
@@ -0,0 +1,12 @@
+config SCST_SRPT
+ tristate "InfiniBand SCSI RDMA Protocol target support"
+ depends on INFINIBAND && SCST
+ ---help---
+
+ Support for the SCSI RDMA Protocol (SRP) Target driver. The
+ SRP protocol is a protocol that allows an initiator to access
+ a block storage device on another host (target) over a network
+ that supports the RDMA protocol. Currently the RDMA protocol is
+ supported by InfiniBand and by iWarp network hardware. More
+ information about the SRP protocol can be found on the website
+ of the INCITS T10 technical committee (http://www.t10.org/).
diff -uprN orig/linux-2.6.35/drivers/scst/srpt/Makefile linux-2.6.35/drivers/scst/srpt/Makefile
--- orig/linux-2.6.35/drivers/scst/srpt/Makefile
+++ linux-2.6.35/drivers/scst/srpt/Makefile
@@ -0,0 +1,1 @@
+obj-$(CONFIG_SCST_SRPT) += ib_srpt.o
diff -uprN orig/linux-2.6.35/drivers/scst/srpt/ib_dm_mad.h linux-2.6.35/drivers/scst/srpt/ib_dm_mad.h
--- orig/linux-2.6.35/drivers/scst/srpt/ib_dm_mad.h
+++ linux-2.6.35/drivers/scst/srpt/ib_dm_mad.h
@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2006 - 2009 Mellanox Technology Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+#ifndef IB_DM_MAD_H
+#define IB_DM_MAD_H
+
+#include <linux/types.h>
+
+#include <rdma/ib_mad.h>
+
+enum {
+ /*
+ * See also section 13.4.7 Status Field, table 115 MAD Common Status
+ * Field Bit Values and also section 16.3.1.1 Status Field in the
+ * InfiniBand Architecture Specification.
+ */
+ DM_MAD_STATUS_UNSUP_METHOD = 0x0008,
+ DM_MAD_STATUS_UNSUP_METHOD_ATTR = 0x000c,
+ DM_MAD_STATUS_INVALID_FIELD = 0x001c,
+ DM_MAD_STATUS_NO_IOC = 0x0100,
+
+ /*
+ * See also the Device Management chapter, section 16.3.3 Attributes,
+ * table 279 Device Management Attributes in the InfiniBand
+ * Architecture Specification.
+ */
+ DM_ATTR_CLASS_PORT_INFO = 0x01,
+ DM_ATTR_IOU_INFO = 0x10,
+ DM_ATTR_IOC_PROFILE = 0x11,
+ DM_ATTR_SVC_ENTRIES = 0x12
+};
+
+struct ib_dm_hdr {
+ u8 reserved[28];
+};
+
+/*
+ * Structure of management datagram sent by the SRP target implementation.
+ * Contains a management datagram header, reliable multi-packet transaction
+ * protocol (RMPP) header and ib_dm_hdr. Notes:
+ * - The SRP target implementation does not use RMPP or ib_dm_hdr when sending
+ * management datagrams.
+ * - The header size must be exactly 64 bytes (IB_MGMT_DEVICE_HDR), since this
+ * is the header size that is passed to ib_create_send_mad() in ib_srpt.c.
+ * - The maximum supported size for a management datagram when not using RMPP
+ * is 256 bytes -- 64 bytes header and 192 (IB_MGMT_DEVICE_DATA) bytes data.
+ */
+struct ib_dm_mad {
+ struct ib_mad_hdr mad_hdr;
+ struct ib_rmpp_hdr rmpp_hdr;
+ struct ib_dm_hdr dm_hdr;
+ u8 data[IB_MGMT_DEVICE_DATA];
+};
+
+/*
+ * IOUnitInfo as defined in section 16.3.3.3 IOUnitInfo of the InfiniBand
+ * Architecture Specification.
+ */
+struct ib_dm_iou_info {
+ __be16 change_id;
+ u8 max_controllers;
+ u8 op_rom;
+ u8 controller_list[128];
+};
+
+/*
+ * IOControllerprofile as defined in section 16.3.3.4 IOControllerProfile of
+ * the InfiniBand Architecture Specification.
+ */
+struct ib_dm_ioc_profile {
+ __be64 guid;
+ __be32 vendor_id;
+ __be32 device_id;
+ __be16 device_version;
+ __be16 reserved1;
+ __be32 subsys_vendor_id;
+ __be32 subsys_device_id;
+ __be16 io_class;
+ __be16 io_subclass;
+ __be16 protocol;
+ __be16 protocol_version;
+ __be16 service_conn;
+ __be16 initiators_supported;
+ __be16 send_queue_depth;
+ u8 reserved2;
+ u8 rdma_read_depth;
+ __be32 send_size;
+ __be32 rdma_size;
+ u8 op_cap_mask;
+ u8 svc_cap_mask;
+ u8 num_svc_entries;
+ u8 reserved3[9];
+ u8 id_string[64];
+};
+
+struct ib_dm_svc_entry {
+ u8 name[40];
+ __be64 id;
+};
+
+/*
+ * See also section 16.3.3.5 ServiceEntries in the InfiniBand Architecture
+ * Specification. See also section B.7, table B.8 in the T10 SRP r16a document.
+ */
+struct ib_dm_svc_entries {
+ struct ib_dm_svc_entry service_entries[4];
+};
+
+#endif
diff -uprN orig/linux-2.6.35/drivers/scst/srpt/ib_srpt.c linux-2.6.35/drivers/scst/srpt/ib_srpt.c
--- orig/linux-2.6.35/drivers/scst/srpt/ib_srpt.c
+++ linux-2.6.35/drivers/scst/srpt/ib_srpt.c
@@ -0,0 +1,3809 @@
+/*
+ * Copyright (c) 2006 - 2009 Mellanox Technology Inc. All rights reserved.
+ * Copyright (C) 2008 Vladislav Bolkhovitin <vst@...b.net>
+ * Copyright (C) 2008 - 2010 Bart Van Assche <bart.vanassche@...il.com>
+ *
+ * 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 <asm/atomic.h>
+#include "ib_srpt.h"
+#define LOG_PREFIX "ib_srpt" /* Prefix for SCST tracing macros. */
+#include <scst/scst_debug.h>
+
+/* Name of this kernel module. */
+#define DRV_NAME "ib_srpt"
+#define DRV_VERSION "2.1.0-pre"
+#define DRV_RELDATE "(not yet released)"
+#if defined(CONFIG_SCST_DEBUG) || defined(CONFIG_SCST_TRACING)
+/* Flags to be used in SCST debug tracing statements. */
+#define DEFAULT_SRPT_TRACE_FLAGS (TRACE_OUT_OF_MEM | TRACE_MINOR \
+ | TRACE_MGMT | TRACE_SPECIAL)
+/* Name of the entry that will be created under /proc/scsi_tgt/ib_srpt. */
+#define SRPT_PROC_TRACE_LEVEL_NAME "trace_level"
+#endif
+
+#define MELLANOX_SRPT_ID_STRING "SCST SRP target"
+
+MODULE_AUTHOR("Vu Pham");
+MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol target "
+ "v" DRV_VERSION " (" DRV_RELDATE ")");
+MODULE_LICENSE("Dual BSD/GPL");
+
+/*
+ * Local data types.
+ */
+
+enum threading_mode {
+ MODE_ALL_IN_SIRQ = 0,
+ MODE_IB_COMPLETION_IN_THREAD = 1,
+ MODE_IB_COMPLETION_IN_SIRQ = 2,
+};
+
+/*
+ * Global Variables
+ */
+
+static u64 srpt_service_guid;
+/* List of srpt_device structures. */
+static atomic_t srpt_device_count;
+#if defined(CONFIG_SCST_DEBUG) || defined(CONFIG_SCST_TRACING)
+static unsigned long trace_flag = DEFAULT_SRPT_TRACE_FLAGS;
+module_param(trace_flag, long, 0644);
+MODULE_PARM_DESC(trace_flag, "SCST trace flags.");
+#endif
+#if defined(CONFIG_SCST_DEBUG)
+static unsigned long processing_delay_in_us;
+module_param(processing_delay_in_us, long, 0744);
+MODULE_PARM_DESC(processing_delay_in_us,
+ "SRP_CMD processing delay in microseconds. Useful for"
+ " testing the initiator lockup avoidance algorithm.");
+#endif
+
+static int thread = 1;
+module_param(thread, int, 0444);
+MODULE_PARM_DESC(thread,
+ "IB completion and SCSI command processing context. Defaults"
+ " to one, i.e. process IB completions and SCSI commands in"
+ " kernel thread context. 0 means soft IRQ whenever possible"
+ " and 2 means process IB completions in soft IRQ context and"
+ " SCSI commands in kernel thread context.");
+
+static unsigned srp_max_rdma_size = DEFAULT_MAX_RDMA_SIZE;
+module_param(srp_max_rdma_size, int, 0744);
+MODULE_PARM_DESC(srp_max_rdma_size,
+ "Maximum size of SRP RDMA transfers for new connections.");
+
+static unsigned srp_max_message_size = DEFAULT_MAX_MESSAGE_SIZE;
+module_param(srp_max_message_size, int, 0444);
+MODULE_PARM_DESC(srp_max_message_size,
+ "Maximum size of SRP control 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_sq_size = DEF_SRPT_SQ_SIZE;
+module_param(srpt_sq_size, int, 0444);
+MODULE_PARM_DESC(srpt_sq_size,
+ "Per-channel send queue (SQ) size.");
+
+static bool srpt_autodetect_cred_req;
+module_param(srpt_autodetect_cred_req, bool, 0444);
+MODULE_PARM_DESC(srpt_autodetect_cred_req,
+ "Whether or not to autodetect whether the initiator supports"
+ " SRP_CRED_REQ.");
+
+static bool use_port_guid_in_session_name;
+module_param(use_port_guid_in_session_name, bool, 0444);
+MODULE_PARM_DESC(use_port_guid_in_session_name,
+ "Use target port ID in the SCST session name such that"
+ " redundant paths between multiport systems can be masked.");
+
+static int srpt_get_u64_x(char *buffer, 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 void srpt_add_one(struct ib_device *device);
+static void srpt_remove_one(struct ib_device *device);
+static void srpt_unregister_mad_agent(struct srpt_device *sdev);
+static void srpt_unmap_sg_to_ib_sge(struct srpt_rdma_ch *ch,
+ struct srpt_ioctx *ioctx);
+static void srpt_release_channel(struct scst_session *scst_sess);
+
+static struct ib_client srpt_client = {
+ .name = DRV_NAME,
+ .add = srpt_add_one,
+ .remove = srpt_remove_one
+};
+
+/**
+ * srpt_test_and_set_channel_state() - Test and set the channel state.
+ *
+ * @ch: RDMA channel.
+ * @old: channel state to compare with.
+ * @new: state to change the channel state to if the current state matches the
+ * argument 'old'.
+ *
+ * Returns the previous channel state.
+ */
+static enum rdma_ch_state
+srpt_test_and_set_channel_state(struct srpt_rdma_ch *ch,
+ enum rdma_ch_state old,
+ enum rdma_ch_state new)
+{
+ return atomic_cmpxchg(&ch->state, old, new);
+}
+
+/**
+ * srpt_event_handler() - Asynchronous IB event callback function.
+ *
+ * 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;
+
+ sdev = ib_get_client_data(event->device, &srpt_client);
+ if (!sdev || sdev->device != event->device)
+ return;
+
+ TRACE_DBG("ASYNC event= %d on device= %s",
+ event->event, sdev->device->name);
+
+ switch (event->event) {
+ case IB_EVENT_PORT_ERR:
+ if (event->element.port_num <= sdev->device->phys_port_cnt) {
+ sport = &sdev->port[event->element.port_num - 1];
+ sport->lid = 0;
+ sport->sm_lid = 0;
+ }
+ 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:
+ /*
+ * Refresh port data asynchronously. Note: it is safe to call
+ * schedule_work() even if &sport->work is already on the
+ * global workqueue because schedule_work() tests for the
+ * work_pending() condition before adding &sport->work to the
+ * global work queue.
+ */
+ if (event->element.port_num <= sdev->device->phys_port_cnt) {
+ sport = &sdev->port[event->element.port_num - 1];
+ if (!sport->lid && !sport->sm_lid)
+ schedule_work(&sport->work);
+ }
+ break;
+ default:
+ PRINT_ERROR("received unrecognized IB event %d", event->event);
+ break;
+ }
+}
+
+/**
+ * srpt_srq_event() - SRQ event callback function.
+ */
+static void srpt_srq_event(struct ib_event *event, void *ctx)
+{
+ PRINT_INFO("SRQ event %d", event->event);
+}
+
+/**
+ * srpt_qp_event() - QP event callback function.
+ */
+static void srpt_qp_event(struct ib_event *event, struct srpt_rdma_ch *ch)
+{
+ TRACE_DBG("QP event %d on cm_id=%p sess_name=%s state=%d",
+ event->event, ch->cm_id, ch->sess_name,
+ atomic_read(&ch->state));
+
+ switch (event->event) {
+ case IB_EVENT_COMM_EST:
+ ib_cm_notify(ch->cm_id, event->event);
+ break;
+ case IB_EVENT_QP_LAST_WQE_REACHED:
+ if (srpt_test_and_set_channel_state(ch, RDMA_CHANNEL_LIVE,
+ RDMA_CHANNEL_DISCONNECTING) == RDMA_CHANNEL_LIVE) {
+ PRINT_INFO("disconnected session %s.", ch->sess_name);
+ ib_send_cm_dreq(ch->cm_id, NULL, 0);
+ }
+ break;
+ default:
+ PRINT_ERROR("received unrecognized IB QP event %d",
+ event->event);
+ break;
+ }
+}
+
+/**
+ * srpt_set_ioc() - Helper function for initializing an IOUnitInfo structure.
+ *
+ * @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.
+ *
+ * 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;
+ cif->resp_time_value = 20;
+
+ mad->mad_hdr.status = 0;
+}
+
+/**
+ * srpt_get_iou() - Write IOUnitInfo to a management datagram.
+ *
+ * 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 = __constant_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.
+ *
+ * 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_device *sdev, u32 slot,
+ struct ib_dm_mad *mad)
+{
+ struct ib_dm_ioc_profile *iocp;
+
+ iocp = (struct ib_dm_ioc_profile *)mad->data;
+
+ if (!slot || slot > 16) {
+ mad->mad_hdr.status = __constant_cpu_to_be16(DM_MAD_STATUS_INVALID_FIELD);
+ return;
+ }
+
+ if (slot > 2) {
+ mad->mad_hdr.status = __constant_cpu_to_be16(DM_MAD_STATUS_NO_IOC);
+ return;
+ }
+
+ memset(iocp, 0, sizeof *iocp);
+ strcpy(iocp->id_string, MELLANOX_SRPT_ID_STRING);
+ iocp->guid = cpu_to_be64(srpt_service_guid);
+ iocp->vendor_id = cpu_to_be32(sdev->dev_attr.vendor_id);
+ iocp->device_id = cpu_to_be32(sdev->dev_attr.vendor_part_id);
+ iocp->device_version = cpu_to_be16(sdev->dev_attr.hw_ver);
+ iocp->subsys_vendor_id = cpu_to_be32(sdev->dev_attr.vendor_id);
+ iocp->subsys_device_id = 0x0;
+ iocp->io_class = __constant_cpu_to_be16(SRP_REV16A_IB_IO_CLASS);
+ iocp->io_subclass = __constant_cpu_to_be16(SRP_IO_SUBCLASS);
+ iocp->protocol = __constant_cpu_to_be16(SRP_PROTOCOL);
+ iocp->protocol_version = __constant_cpu_to_be16(SRP_PROTOCOL_VERSION);
+ iocp->send_queue_depth = cpu_to_be16(sdev->srq_size);
+ iocp->rdma_read_depth = 4;
+ iocp->send_size = cpu_to_be32(srp_max_message_size);
+ iocp->rdma_size = cpu_to_be32(min(max(srp_max_rdma_size, 256U),
+ 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.
+ *
+ * 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 = __constant_cpu_to_be16(DM_MAD_STATUS_INVALID_FIELD);
+ return;
+ }
+
+ if (slot > 2 || lo > hi || hi > 1) {
+ mad->mad_hdr.status = __constant_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: source 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->sdev, 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 =
+ __constant_cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD_ATTR);
+ break;
+ }
+}
+
+/**
+ * srpt_mad_send_handler() - Post MAD-send callback function.
+ */
+static void srpt_mad_send_handler(struct ib_mad_agent *mad_agent,
+ struct ib_mad_send_wc *mad_wc)
+{
+ ib_destroy_ah(mad_wc->send_buf->ah);
+ ib_free_send_mad(mad_wc->send_buf);
+}
+
+/**
+ * srpt_mad_recv_handler() - MAD reception callback function.
+ */
+static void srpt_mad_recv_handler(struct ib_mad_agent *mad_agent,
+ 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);
+ 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 =
+ __constant_cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD_ATTR);
+ break;
+ default:
+ dm_mad->mad_hdr.status =
+ __constant_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:
+ ib_destroy_ah(ah);
+err:
+ ib_free_recv_mad(mad_wc);
+}
+
+/**
+ * srpt_refresh_port() - Configure a 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;
+
+ 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)
+ goto err_mod_port;
+
+ ret = ib_query_port(sport->sdev->device, sport->port, &port_attr);
+ if (ret)
+ goto err_query_port;
+
+ sport->sm_lid = port_attr.sm_lid;
+ sport->lid = port_attr.lid;
+
+ ret = ib_query_gid(sport->sdev->device, sport->port, 0, &sport->gid);
+ if (ret)
+ goto err_query_port;
+
+ if (!sport->mad_agent) {
+ memset(®_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,
+ ®_req, 0,
+ srpt_mad_send_handler,
+ srpt_mad_recv_handler,
+ sport);
+ if (IS_ERR(sport->mad_agent)) {
+ ret = PTR_ERR(sport->mad_agent);
+ sport->mad_agent = NULL;
+ goto err_query_port;
+ }
+ }
+
+ return 0;
+
+err_query_port:
+
+ port_modify.set_port_cap_mask = 0;
+ port_modify.clr_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP;
+ ib_modify_port(sport->sdev->device, sport->port, 0, &port_modify);
+
+err_mod_port:
+
+ return ret;
+}
+
+/**
+ * srpt_unregister_mad_agent() - Unregister MAD callback functions.
+ *
+ * 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)
+ PRINT_ERROR("%s", "disabling MAD processing failed.");
+ if (sport->mad_agent) {
+ ib_unregister_mad_agent(sport->mad_agent);
+ sport->mad_agent = NULL;
+ }
+ }
+}
+
+/**
+ * srpt_alloc_ioctx() - Allocate and initialize an SRPT I/O context structure.
+ */
+static struct srpt_ioctx *srpt_alloc_ioctx(struct srpt_device *sdev)
+{
+ struct srpt_ioctx *ioctx;
+
+ ioctx = kmalloc(sizeof *ioctx, GFP_KERNEL);
+ if (!ioctx)
+ goto out;
+
+ ioctx->buf = kzalloc(srp_max_message_size, GFP_KERNEL);
+ if (!ioctx->buf)
+ goto out_free_ioctx;
+
+ ioctx->dma = ib_dma_map_single(sdev->device, ioctx->buf,
+ srp_max_message_size, DMA_BIDIRECTIONAL);
+ if (ib_dma_mapping_error(sdev->device, ioctx->dma))
+ goto out_free_buf;
+
+ return ioctx;
+
+out_free_buf:
+ kfree(ioctx->buf);
+out_free_ioctx:
+ kfree(ioctx);
+out:
+ return NULL;
+}
+
+/**
+ * srpt_free_ioctx() - Deallocate an SRPT I/O context structure.
+ */
+static void srpt_free_ioctx(struct srpt_device *sdev, struct srpt_ioctx *ioctx)
+{
+ if (!ioctx)
+ return;
+
+ ib_dma_unmap_single(sdev->device, ioctx->dma,
+ srp_max_message_size, DMA_BIDIRECTIONAL);
+ kfree(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.
+ * @ioctx_ring: Pointer to an array of I/O contexts.
+ * @ring_size: Number of elements in the I/O context ring.
+ * @flags: Flags to be set in the ring index.
+ */
+static int srpt_alloc_ioctx_ring(struct srpt_device *sdev,
+ struct srpt_ioctx **ioctx_ring,
+ int ring_size,
+ int flags)
+{
+ int res;
+ int i;
+
+ res = -ENOMEM;
+ for (i = 0; i < ring_size; ++i) {
+ ioctx_ring[i] = srpt_alloc_ioctx(sdev);
+
+ if (!ioctx_ring[i])
+ goto err;
+
+ EXTRACHECKS_WARN_ON(i & flags);
+ ioctx_ring[i]->index = i | flags;
+ }
+ res = 0;
+ goto out;
+
+err:
+ while (--i >= 0) {
+ srpt_free_ioctx(sdev, ioctx_ring[i]);
+ ioctx_ring[i] = NULL;
+ }
+out:
+ return res;
+}
+
+/**
+ * srpt_free_ioctx_ring() - Free the ring of SRPT I/O context structures.
+ */
+static void srpt_free_ioctx_ring(struct srpt_device *sdev,
+ struct srpt_ioctx **ioctx_ring,
+ int ring_size)
+{
+ int i;
+
+ for (i = 0; i < ring_size; ++i) {
+ srpt_free_ioctx(sdev, ioctx_ring[i]);
+ ioctx_ring[i] = NULL;
+ }
+}
+
+/**
+ * srpt_alloc_tti_ring() - Allocate target-to-initiator I/O contexts.
+ */
+static int srpt_alloc_tti_ioctx(struct srpt_rdma_ch *ch)
+{
+ return srpt_alloc_ioctx_ring(ch->sport->sdev, ch->tti_ioctx,
+ ARRAY_SIZE(ch->tti_ioctx),
+ SRPT_OP_TTI);
+}
+
+/**
+ * srpt_free_tti_ring() - Free target-to-initiator I/O contexts.
+ */
+static void srpt_free_tti_ioctx(struct srpt_rdma_ch *ch)
+{
+ srpt_free_ioctx_ring(ch->sport->sdev, ch->tti_ioctx,
+ ARRAY_SIZE(ch->tti_ioctx));
+}
+
+/**
+ * srpt_get_tti_ioctx() - Get a target-to-initiator I/O context.
+ */
+static struct srpt_ioctx *srpt_get_tti_ioctx(struct srpt_rdma_ch *ch)
+{
+ struct srpt_ioctx *ioctx;
+ struct srpt_device *sdev;
+ unsigned long flags;
+
+ sdev = ch->sport->sdev;
+ spin_lock_irqsave(&sdev->spinlock, flags);
+ EXTRACHECKS_WARN_ON(ch->tti_head - ch->tti_tail < 0);
+ if (ch->tti_head - ch->tti_tail < TTI_IOCTX_COUNT)
+ ioctx = ch->tti_ioctx[ch->tti_head++ & TTI_IOCTX_MASK];
+ else
+ ioctx = NULL;
+ spin_unlock_irqrestore(&sdev->spinlock, flags);
+ return ioctx;
+}
+
+/**
+ * srpt_put_tti_ioctx() - Put back a target-to-initiator I/O context.
+ */
+static void srpt_put_tti_ioctx(struct srpt_rdma_ch *ch)
+{
+ struct srpt_device *sdev;
+ unsigned long flags;
+
+ sdev = ch->sport->sdev;
+ spin_lock_irqsave(&sdev->spinlock, flags);
+ EXTRACHECKS_WARN_ON(ch->tti_head - ch->tti_tail < 0);
+ ch->tti_tail++;
+ EXTRACHECKS_WARN_ON(ch->tti_head - ch->tti_tail < 0);
+ spin_unlock_irqrestore(&sdev->spinlock, flags);
+}
+
+/**
+ * srpt_get_cmd_state() - Get the state of a SCSI command.
+ */
+static enum srpt_command_state srpt_get_cmd_state(struct srpt_ioctx *ioctx)
+{
+ BUG_ON(!ioctx);
+
+ return atomic_read(&ioctx->state);
+}
+
+/**
+ * srpt_set_cmd_state() - Set the state of a SCSI command.
+ * @new: New state to be set.
+ *
+ * Does not modify the state of aborted commands. Returns the previous command
+ * state.
+ */
+static enum srpt_command_state srpt_set_cmd_state(struct srpt_ioctx *ioctx,
+ enum srpt_command_state new)
+{
+ enum srpt_command_state previous;
+
+ BUG_ON(!ioctx);
+
+ do {
+ previous = atomic_read(&ioctx->state);
+ } while (previous != SRPT_STATE_DONE
+ && atomic_cmpxchg(&ioctx->state, previous, new) != previous);
+
+ return previous;
+}
+
+/**
+ * srpt_test_and_set_cmd_state() - Test and set the state of a command.
+ * @old: State to compare against.
+ * @new: New state to be set if the current state matches 'old'.
+ *
+ * Returns the previous command state.
+ */
+static enum srpt_command_state
+srpt_test_and_set_cmd_state(struct srpt_ioctx *ioctx,
+ enum srpt_command_state old,
+ enum srpt_command_state new)
+{
+ WARN_ON(!ioctx);
+ WARN_ON(old == SRPT_STATE_DONE);
+ WARN_ON(new == SRPT_STATE_NEW);
+
+ return atomic_cmpxchg(&ioctx->state, old, new);
+}
+
+/**
+ * srpt_post_recv() - Post an IB receive request.
+ */
+static int srpt_post_recv(struct srpt_device *sdev, struct srpt_ioctx *ioctx)
+{
+ struct ib_sge list;
+ struct ib_recv_wr wr, *bad_wr;
+
+ wr.wr_id = ioctx->index | SRPT_OP_RECV;
+
+ list.addr = ioctx->dma;
+ list.length = srp_max_message_size;
+ list.lkey = sdev->mr->lkey;
+
+ wr.next = NULL;
+ wr.sg_list = &list;
+ wr.num_sge = 1;
+
+ return ib_post_srq_recv(sdev->srq, &wr, &bad_wr);
+}
+
+/**
+ * srpt_post_send() - Post an IB send request.
+ * @ch: RDMA channel to post the send request on.
+ * @ioctx: I/O context of the send request.
+ * @len: length of the request to be sent in bytes.
+ *
+ * Returns zero upon success and a non-zero value upon failure.
+ */
+static int srpt_post_send(struct srpt_rdma_ch *ch, struct srpt_ioctx *ioctx,
+ int len)
+{
+ struct ib_sge list;
+ struct ib_send_wr wr, *bad_wr;
+ struct srpt_device *sdev = ch->sport->sdev;
+ int ret;
+
+ ret = -ENOMEM;
+ if (atomic_dec_return(&ch->sq_wr_avail) < 0) {
+ PRINT_ERROR("%s[%d]: send queue full", __func__, __LINE__);
+ goto out;
+ }
+
+ ib_dma_sync_single_for_device(sdev->device, ioctx->dma,
+ len, DMA_TO_DEVICE);
+
+ list.addr = ioctx->dma;
+ list.length = len;
+ list.lkey = sdev->mr->lkey;
+
+ wr.next = NULL;
+ wr.wr_id = ioctx->index;
+ wr.sg_list = &list;
+ wr.num_sge = 1;
+ wr.opcode = IB_WR_SEND;
+ wr.send_flags = IB_SEND_SIGNALED;
+
+ ret = ib_post_send(ch->qp, &wr, &bad_wr);
+
+out:
+ if (ret < 0)
+ atomic_inc(&ch->sq_wr_avail);
+ return ret;
+}
+
+/**
+ * srpt_get_desc_tbl() - Parse the data descriptors of an SRP_CMD request.
+ * @ioctx: Pointer to the I/O context associated with the request.
+ * @srp_cmd: Pointer to the SRP_CMD request data.
+ * @dir: Pointer to the variable to which the transfer direction will be
+ * written.
+ * @data_len: Pointer to the variable to which the total data length of all
+ * descriptors in the SRP_CMD request will be written.
+ *
+ * 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_ioctx *ioctx, struct srp_cmd *srp_cmd,
+ scst_data_direction *dir, u64 *data_len)
+{
+ struct srp_indirect_buf *idb;
+ struct srp_direct_buf *db;
+ unsigned add_cdb_offset;
+ int ret;
+
+ /*
+ * 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));
+
+ BUG_ON(!dir);
+ BUG_ON(!data_len);
+
+ ret = 0;
+ *data_len = 0;
+
+ /*
+ * 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.
+ */
+ *dir = SCST_DATA_NONE;
+ if (srp_cmd->buf_fmt & 0xf)
+ /* DATA-IN: transfer data from target to initiator. */
+ *dir = SCST_DATA_READ;
+ else if (srp_cmd->buf_fmt >> 4)
+ /* DATA-OUT: transfer data from initiator to target. */
+ *dir = SCST_DATA_WRITE;
+
+ /*
+ * 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".
+ */
+ add_cdb_offset = srp_cmd->add_cdb_len & ~3;
+ if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_DIRECT) ||
+ ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_DIRECT)) {
+ ioctx->n_rbuf = 1;
+ ioctx->rbufs = &ioctx->single_rbuf;
+
+ db = (struct srp_direct_buf *)(srp_cmd->add_data
+ + add_cdb_offset);
+ memcpy(ioctx->rbufs, db, sizeof *db);
+ *data_len = be32_to_cpu(db->len);
+ } else if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_INDIRECT) ||
+ ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_INDIRECT)) {
+ idb = (struct srp_indirect_buf *)(srp_cmd->add_data
+ + add_cdb_offset);
+
+ ioctx->n_rbuf = be32_to_cpu(idb->table_desc.len) / sizeof *db;
+
+ if (ioctx->n_rbuf >
+ (srp_cmd->data_out_desc_cnt + srp_cmd->data_in_desc_cnt)) {
+ PRINT_ERROR("received unsupported SRP_CMD request type"
+ " (%u out + %u in != %u / %zu)",
+ srp_cmd->data_out_desc_cnt,
+ srp_cmd->data_in_desc_cnt,
+ be32_to_cpu(idb->table_desc.len),
+ sizeof(*db));
+ ioctx->n_rbuf = 0;
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (ioctx->n_rbuf == 1)
+ ioctx->rbufs = &ioctx->single_rbuf;
+ else {
+ ioctx->rbufs =
+ kmalloc(ioctx->n_rbuf * sizeof *db, GFP_ATOMIC);
+ if (!ioctx->rbufs) {
+ ioctx->n_rbuf = 0;
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+
+ db = idb->desc_list;
+ memcpy(ioctx->rbufs, db, ioctx->n_rbuf * sizeof *db);
+ *data_len = be32_to_cpu(idb->len);
+ }
+out:
+ return ret;
+}
+
+/**
+ * srpt_init_ch_qp() - Initialize queue pair attributes.
+ *
+ * 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;
+
+ attr = kzalloc(sizeof *attr, GFP_KERNEL);
+ if (!attr)
+ return -ENOMEM;
+
+ attr->qp_state = IB_QPS_INIT;
+ attr->qp_access_flags = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_READ |
+ IB_ACCESS_REMOTE_WRITE;
+ attr->port_num = ch->sport->port;
+ attr->pkey_index = 0;
+
+ 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;
+
+ qp_attr.qp_state = IB_QPS_RTR;
+ ret = ib_cm_init_qp_attr(ch->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->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_req_lim_delta() - Compute req_lim delta.
+ *
+ * Compute by how much req_lim changed since the last time this function has
+ * been called. This value is necessary for filling in the REQUEST LIMIT DELTA
+ * field of an SRP_RSP response.
+ *
+ * Side Effect:
+ * Resets ch->req_lim_delta.
+ *
+ * Note:
+ * The caller must either pass the returned value to the initiator in the
+ * REQUEST LIMIT DELTA field of an SRP information unit or pass the returned
+ * value to srpt_undo_req_lim_delta(). Any other approach will result in an
+ * SRP protocol violation.
+ */
+static int srpt_req_lim_delta(struct srpt_rdma_ch *ch)
+{
+ return atomic_xchg(&ch->req_lim_delta, 0);
+}
+
+/**
+ * srpt_undo_req_lim_delta() - Undo the side effect of srpt_req_lim_delta().
+ * @ch: Channel pointer.
+ * @delta: return value of srpt_req_lim_delta().
+ */
+static void srpt_undo_req_lim_delta(struct srpt_rdma_ch *ch, int delta)
+{
+ atomic_add(delta, &ch->req_lim_delta);
+}
+
+/**
+ * srpt_send_cred_req() - Send an SRP_CRED_REQ IU to the initiator.
+ *
+ * The previous value of ch->req_lim_delta is restored if sending fails
+ * synchronously or asynchronously.
+ */
+static void srpt_send_cred_req(struct srpt_rdma_ch *ch, s32 req_lim_delta)
+{
+ struct srpt_ioctx *ioctx;
+ struct srp_cred_req *srp_cred_req;
+ int res;
+
+ ioctx = srpt_get_tti_ioctx(ch);
+ if (!ioctx) {
+ PRINT_ERROR("%s",
+ "Sending SRP_CRED_REQ failed -- no I/O context"
+ " available ! This will sooner or later result"
+ " in an initiator lockup.");
+ goto err;
+ }
+
+ BUG_ON(!ch);
+ srp_cred_req = ioctx->buf;
+ BUG_ON(!srp_cred_req);
+ memset(srp_cred_req, 0, sizeof(*srp_cred_req));
+ srp_cred_req->opcode = SRP_CRED_REQ;
+ srp_cred_req->req_lim_delta = cpu_to_be32(req_lim_delta);
+ srp_cred_req->tag = __constant_cpu_to_be64(0);
+ res = srpt_post_send(ch, ioctx, sizeof(*srp_cred_req));
+ if (res) {
+ PRINT_ERROR("sending SRP_CRED_REQ failed (res = %d)", res);
+ goto err_put;
+ }
+
+ TRACE_DBG("Sent SRP_CRED_REQ with req_lim_delta = %d and tag %lld",
+ req_lim_delta, 0ULL);
+
+ goto out;
+
+err_put:
+ srpt_put_tti_ioctx(ch);
+err:
+ srpt_undo_req_lim_delta(ch, req_lim_delta);
+out:
+ return;
+}
+
+/**
+ * srpt_reset_ioctx() - Free up resources and post again for receiving.
+ *
+ * Note: Do NOT modify *ioctx after this function has finished. Otherwise a
+ * race condition will be triggered between srpt_rcv_completion() and the
+ * caller of this function on *ioctx.
+ */
+static void srpt_reset_ioctx(struct srpt_rdma_ch *ch, struct srpt_ioctx *ioctx,
+ bool inc_req_lim)
+{
+ BUG_ON(!ch);
+ BUG_ON(!ioctx);
+
+ WARN_ON(srpt_get_cmd_state(ioctx) != SRPT_STATE_DONE);
+
+ ioctx->scmnd = NULL;
+ ioctx->ch = NULL;
+
+ /*
+ * If the WARN_ON() below gets triggered this means that
+ * srpt_unmap_sg_to_ib_sge() has not been called before
+ * scst_tgt_cmd_done().
+ */
+ WARN_ON(ioctx->mapped_sg_count);
+
+ if (ioctx->n_rbuf > 1) {
+ kfree(ioctx->rbufs);
+ ioctx->rbufs = NULL;
+ ioctx->n_rbuf = 0;
+ }
+
+ if (srpt_post_recv(ch->sport->sdev, ioctx))
+ PRINT_ERROR("%s", "SRQ post_recv failed - this is serious.");
+ else if (inc_req_lim) {
+ int req_lim;
+
+ atomic_inc(&ch->req_lim_delta);
+ req_lim = atomic_inc_return(&ch->req_lim);
+ if (req_lim < 0 || req_lim > ch->rq_size)
+ PRINT_ERROR("req_lim = %d out of range %d .. %d",
+ req_lim, 0, ch->rq_size);
+ if (atomic_read(&ch->supports_cred_req)) {
+ if (req_lim == ch->rq_size / 2
+ && atomic_read(&ch->req_lim_delta) > ch->rq_size/4)
+ srpt_send_cred_req(ch, srpt_req_lim_delta(ch));
+ } else {
+ if (atomic_add_unless(&ch->req_lim_waiter_count, -1, 0))
+ complete(&ch->req_lim_compl);
+ }
+ }
+}
+
+/**
+ * srpt_abort_scst_cmd() - Abort a SCSI command.
+ * @ioctx: I/O context associated with the SCSI command.
+ * @context: Preferred execution context.
+ */
+static void srpt_abort_scst_cmd(struct srpt_ioctx *ioctx,
+ enum scst_exec_context context)
+{
+ struct scst_cmd *scmnd;
+ enum srpt_command_state state;
+
+ BUG_ON(!ioctx);
+
+ /*
+ * If the command is in a state where the SCST core is waiting for the
+ * ib_srpt driver, change the state to the next state. Changing the
+ * state of the command from SRPT_NEED_DATA to SRPT_STATE_DATA_IN
+ * ensures that srpt_xmit_response() will call this function a second
+ * time.
+ */
+ state = srpt_test_and_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA,
+ SRPT_STATE_DATA_IN);
+ if (state != SRPT_STATE_NEED_DATA) {
+ state = srpt_test_and_set_cmd_state(ioctx, SRPT_STATE_DATA_IN,
+ SRPT_STATE_DONE);
+ if (state != SRPT_STATE_DATA_IN) {
+ state = srpt_test_and_set_cmd_state(ioctx,
+ SRPT_STATE_CMD_RSP_SENT, SRPT_STATE_DONE);
+ if (state != SRPT_STATE_CMD_RSP_SENT)
+ state = srpt_test_and_set_cmd_state(ioctx,
+ SRPT_STATE_MGMT_RSP_SENT,
+ SRPT_STATE_DONE);
+ }
+ }
+ if (state == SRPT_STATE_DONE)
+ goto out;
+
+ scmnd = ioctx->scmnd;
+ WARN_ON(!scmnd);
+ if (!scmnd)
+ goto out;
+
+ WARN_ON(ioctx != scst_cmd_get_tgt_priv(scmnd));
+
+ TRACE_DBG("Aborting cmd with state %d and tag %lld",
+ state, scst_cmd_get_tag(scmnd));
+
+ switch (state) {
+ case SRPT_STATE_NEW:
+ /*
+ * Do nothing - defer abort processing until
+ * srpt_xmit_response() is invoked.
+ */
+ WARN_ON(!scst_cmd_aborted(scmnd));
+ break;
+ case SRPT_STATE_DATA_IN:
+ /*
+ * Invocation of srpt_pending_cmd_timeout() after
+ * srpt_handle_rdma_comp() set the state to SRPT_STATE_DATA_IN
+ * and before srpt_xmit_response() set the state to
+ * SRPT_STATE_CMD_RSP_SENT. Ignore the timeout and let
+ * srpt_handle_xmit_response() proceed.
+ */
+ break;
+ case SRPT_STATE_NEED_DATA:
+ /* SCST_DATA_WRITE - RDMA read error or RDMA read timeout. */
+ scst_rx_data(ioctx->scmnd, SCST_RX_STATUS_ERROR, context);
+ break;
+ case SRPT_STATE_CMD_RSP_SENT:
+ /*
+ * SRP_RSP sending failed or the SRP_RSP send completion has
+ * not been received in time.
+ */
+ srpt_unmap_sg_to_ib_sge(ioctx->ch, ioctx);
+ scst_set_delivery_status(scmnd, SCST_CMD_DELIVERY_ABORTED);
+ scst_tgt_cmd_done(scmnd, context);
+ break;
+ case SRPT_STATE_MGMT_RSP_SENT:
+ /*
+ * Management command response sending failed. This state is
+ * never reached since there is no scmnd associated with
+ * management commands. Note: the SCST core frees these
+ * commands immediately after srpt_tsk_mgmt_done() returned.
+ */
+ WARN_ON("ERROR: unexpected command state");
+ break;
+ default:
+ WARN_ON("ERROR: unexpected command state");
+ break;
+ }
+
+out:
+ ;
+}
+
+/**
+ * srpt_handle_send_err_comp() - Process an IB_WC_SEND or RDMA error completion.
+ */
+static void srpt_handle_send_err_comp(struct srpt_rdma_ch *ch, u64 wr_id,
+ enum scst_exec_context context)
+{
+ struct srpt_ioctx *ioctx;
+ struct srpt_device *sdev = ch->sport->sdev;
+ enum srpt_command_state state;
+ struct scst_cmd *scmnd;
+
+ EXTRACHECKS_WARN_ON(wr_id & SRPT_OP_RECV);
+
+ ioctx = sdev->ioctx_ring[wr_id & ~SRPT_OP_TTI];
+
+ if ((wr_id & SRPT_OP_TTI) == 0) {
+ state = srpt_get_cmd_state(ioctx);
+ scmnd = ioctx->scmnd;
+
+ EXTRACHECKS_WARN_ON(state != SRPT_STATE_CMD_RSP_SENT
+ && state != SRPT_STATE_MGMT_RSP_SENT
+ && state != SRPT_STATE_NEED_DATA
+ && state != SRPT_STATE_DONE);
+
+ if (state != SRPT_STATE_DONE) {
+ if (scmnd)
+ srpt_abort_scst_cmd(ioctx, context);
+ else {
+ srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
+ srpt_reset_ioctx(ch, ioctx, 1);
+ }
+ } else
+ PRINT_ERROR("Received more than one IB error completion"
+ " for wr_id = %u.", (unsigned)wr_id);
+ } else {
+ struct srp_cred_req *srp_cred_req;
+ s32 req_lim_delta;
+
+ srp_cred_req = ioctx->buf;
+ req_lim_delta = be32_to_cpu(srp_cred_req->req_lim_delta);
+ srpt_undo_req_lim_delta(ch, req_lim_delta);
+ srpt_put_tti_ioctx(ch);
+ PRINT_ERROR("Sending SRP_CRED_REQ with delta = %d failed.",
+ req_lim_delta);
+ }
+}
+
+/**
+ * srpt_handle_send_comp() - Process an IB send completion notification.
+ */
+static void srpt_handle_send_comp(struct srpt_rdma_ch *ch,
+ struct srpt_ioctx *ioctx,
+ enum scst_exec_context context)
+{
+ enum srpt_command_state state;
+
+ atomic_inc(&ch->sq_wr_avail);
+
+ state = srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
+
+ EXTRACHECKS_WARN_ON(state != SRPT_STATE_CMD_RSP_SENT
+ && state != SRPT_STATE_MGMT_RSP_SENT
+ && state != SRPT_STATE_DONE);
+
+ if (state != SRPT_STATE_DONE) {
+ struct scst_cmd *scmnd;
+
+ scmnd = ioctx->scmnd;
+ EXTRACHECKS_WARN_ON((state == SRPT_STATE_MGMT_RSP_SENT)
+ != (scmnd == NULL));
+ if (scmnd) {
+ srpt_unmap_sg_to_ib_sge(ch, ioctx);
+ scst_tgt_cmd_done(scmnd, context);
+ } else
+ srpt_reset_ioctx(ch, ioctx, 1);
+ } else {
+ PRINT_ERROR("IB completion has been received too late for"
+ " wr_id = %u.", ioctx->index);
+ }
+}
+
+/**
+ * srpt_handle_rdma_comp() - Process an IB RDMA completion notification.
+ */
+static void srpt_handle_rdma_comp(struct srpt_rdma_ch *ch,
+ struct srpt_ioctx *ioctx,
+ enum scst_exec_context context)
+{
+ enum srpt_command_state state;
+ struct scst_cmd *scmnd;
+
+ EXTRACHECKS_WARN_ON(ioctx->n_rdma <= 0);
+ atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
+
+ scmnd = ioctx->scmnd;
+ if (scmnd) {
+ state = srpt_test_and_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA,
+ SRPT_STATE_DATA_IN);
+
+ EXTRACHECKS_WARN_ON(state != SRPT_STATE_NEED_DATA);
+
+ scst_rx_data(ioctx->scmnd, SCST_RX_STATUS_SUCCESS, context);
+ } else
+ PRINT_ERROR("%s[%d]: scmnd == NULL", __func__, __LINE__);
+}
+
+/**
+ * srpt_build_cmd_rsp() - Build an 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.
+ * @sense_data: pointer to sense data to be included in the response.
+ * @sense_data_len: length in bytes of the sense data.
+ *
+ * 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_ioctx *ioctx, s32 req_lim_delta,
+ u64 tag, int status,
+ const u8 *sense_data, int sense_data_len)
+{
+ struct srp_rsp *srp_rsp;
+ int max_sense_len;
+
+ /*
+ * The lowest bit of all SAM-3 status codes is zero (see also
+ * paragraph 5.3 in SAM-3).
+ */
+ EXTRACHECKS_WARN_ON(status & 1);
+
+ srp_rsp = 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(req_lim_delta);
+ srp_rsp->tag = tag;
+ srp_rsp->status = status;
+
+ if (!SCST_SENSE_VALID(sense_data))
+ sense_data_len = 0;
+ else {
+ BUILD_BUG_ON(MIN_MAX_MESSAGE_SIZE <= sizeof(*srp_rsp));
+ max_sense_len = ch->max_ti_iu_len - sizeof(*srp_rsp);
+ if (sense_data_len > max_sense_len) {
+ PRINT_WARNING("truncated sense data from %d to %d"
+ " bytes", 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_ioctx *ioctx, s32 req_lim_delta,
+ u8 rsp_code, u64 tag)
+{
+ struct srp_rsp *srp_rsp;
+ int resp_data_len;
+ int resp_len;
+
+ resp_data_len = (rsp_code == SRP_TSK_MGMT_SUCCESS) ? 0 : 4;
+ resp_len = sizeof(*srp_rsp) + resp_data_len;
+
+ srp_rsp = ioctx->buf;
+ memset(srp_rsp, 0, sizeof *srp_rsp);
+
+ srp_rsp->opcode = SRP_RSP;
+ srp_rsp->req_lim_delta = cpu_to_be32(req_lim_delta);
+ srp_rsp->tag = tag;
+
+ if (rsp_code != SRP_TSK_MGMT_SUCCESS) {
+ 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;
+}
+
+/**
+ * srpt_handle_cmd() - Process SRP_CMD.
+ */
+static int srpt_handle_cmd(struct srpt_rdma_ch *ch, struct srpt_ioctx *ioctx,
+ enum scst_exec_context context)
+{
+ struct scst_cmd *scmnd;
+ struct srp_cmd *srp_cmd;
+ scst_data_direction dir;
+ u64 data_len;
+ int ret;
+
+ srp_cmd = ioctx->buf;
+
+ scmnd = scst_rx_cmd(ch->scst_sess, (u8 *) &srp_cmd->lun,
+ sizeof srp_cmd->lun, srp_cmd->cdb,
+ sizeof srp_cmd->cdb, context);
+ if (!scmnd)
+ goto err;
+
+ ioctx->scmnd = scmnd;
+
+ ret = srpt_get_desc_tbl(ioctx, srp_cmd, &dir, &data_len);
+ if (ret) {
+ scst_set_cmd_error(scmnd,
+ SCST_LOAD_SENSE(scst_sense_invalid_field_in_cdb));
+ goto err;
+ }
+
+ switch (srp_cmd->task_attr) {
+ case SRP_CMD_HEAD_OF_Q:
+ scst_cmd_set_queue_type(scmnd, SCST_CMD_QUEUE_HEAD_OF_QUEUE);
+ break;
+ case SRP_CMD_ORDERED_Q:
+ scst_cmd_set_queue_type(scmnd, SCST_CMD_QUEUE_ORDERED);
+ break;
+ case SRP_CMD_SIMPLE_Q:
+ scst_cmd_set_queue_type(scmnd, SCST_CMD_QUEUE_SIMPLE);
+ break;
+ case SRP_CMD_ACA:
+ scst_cmd_set_queue_type(scmnd, SCST_CMD_QUEUE_ACA);
+ break;
+ default:
+ scst_cmd_set_queue_type(scmnd, SCST_CMD_QUEUE_ORDERED);
+ break;
+ }
+
+ scst_cmd_set_tag(scmnd, srp_cmd->tag);
+ scst_cmd_set_tgt_priv(scmnd, ioctx);
+ scst_cmd_set_expected(scmnd, dir, data_len);
+ scst_cmd_init_done(scmnd, context);
+
+ return 0;
+
+err:
+ return -1;
+}
+
+/**
+ * srpt_handle_tsk_mgmt() - Process an SRP_TSK_MGMT information unit.
+ *
+ * Returns SCST_MGMT_STATUS_SUCCESS upon success.
+ *
+ * Each task management function is performed by calling one of the
+ * scst_rx_mgmt_fn*() functions. These functions will either report failure
+ * or process the task management function asynchronously. The function
+ * srpt_tsk_mgmt_done() will be called by the SCST core upon completion of the
+ * task management function. When srpt_handle_tsk_mgmt() reports failure
+ * (i.e. returns -1) a response will have been built in ioctx->buf. This
+ * information unit has to be sent back by the caller.
+ *
+ * For more information about SRP_TSK_MGMT information units, see also section
+ * 6.7 in the SRP r16a document.
+ */
+static u8 srpt_handle_tsk_mgmt(struct srpt_rdma_ch *ch,
+ struct srpt_ioctx *ioctx)
+{
+ struct srp_tsk_mgmt *srp_tsk;
+ struct srpt_mgmt_ioctx *mgmt_ioctx;
+ int ret;
+
+ srp_tsk = ioctx->buf;
+
+ TRACE_DBG("recv_tsk_mgmt= %d for task_tag= %lld"
+ " using tag= %lld cm_id= %p sess= %p",
+ srp_tsk->tsk_mgmt_func, srp_tsk->task_tag, srp_tsk->tag,
+ ch->cm_id, ch->scst_sess);
+
+ ret = SCST_MGMT_STATUS_FAILED;
+ mgmt_ioctx = kmalloc(sizeof *mgmt_ioctx, GFP_ATOMIC);
+ if (!mgmt_ioctx)
+ goto err;
+
+ mgmt_ioctx->ioctx = ioctx;
+ mgmt_ioctx->ch = ch;
+ mgmt_ioctx->tag = srp_tsk->tag;
+
+ switch (srp_tsk->tsk_mgmt_func) {
+ case SRP_TSK_ABORT_TASK:
+ TRACE_DBG("%s", "Processing SRP_TSK_ABORT_TASK");
+ ret = scst_rx_mgmt_fn_tag(ch->scst_sess,
+ SCST_ABORT_TASK,
+ srp_tsk->task_tag,
+ SCST_ATOMIC, mgmt_ioctx);
+ break;
+ case SRP_TSK_ABORT_TASK_SET:
+ TRACE_DBG("%s", "Processing SRP_TSK_ABORT_TASK_SET");
+ ret = scst_rx_mgmt_fn_lun(ch->scst_sess,
+ SCST_ABORT_TASK_SET,
+ (u8 *) &srp_tsk->lun,
+ sizeof srp_tsk->lun,
+ SCST_ATOMIC, mgmt_ioctx);
+ break;
+ case SRP_TSK_CLEAR_TASK_SET:
+ TRACE_DBG("%s", "Processing SRP_TSK_CLEAR_TASK_SET");
+ ret = scst_rx_mgmt_fn_lun(ch->scst_sess,
+ SCST_CLEAR_TASK_SET,
+ (u8 *) &srp_tsk->lun,
+ sizeof srp_tsk->lun,
+ SCST_ATOMIC, mgmt_ioctx);
+ break;
+ case SRP_TSK_LUN_RESET:
+ TRACE_DBG("%s", "Processing SRP_TSK_LUN_RESET");
+ ret = scst_rx_mgmt_fn_lun(ch->scst_sess,
+ SCST_LUN_RESET,
+ (u8 *) &srp_tsk->lun,
+ sizeof srp_tsk->lun,
+ SCST_ATOMIC, mgmt_ioctx);
+ break;
+ case SRP_TSK_CLEAR_ACA:
+ TRACE_DBG("%s", "Processing SRP_TSK_CLEAR_ACA");
+ ret = scst_rx_mgmt_fn_lun(ch->scst_sess,
+ SCST_CLEAR_ACA,
+ (u8 *) &srp_tsk->lun,
+ sizeof srp_tsk->lun,
+ SCST_ATOMIC, mgmt_ioctx);
+ break;
+ default:
+ TRACE_DBG("%s", "Unsupported task management function.");
+ ret = SCST_MGMT_STATUS_FN_NOT_SUPPORTED;
+ }
+
+ if (ret != SCST_MGMT_STATUS_SUCCESS)
+ goto err;
+ return ret;
+
+err:
+ kfree(mgmt_ioctx);
+ return ret;
+}
+
+static void srpt_handle_cred_rsp(struct srpt_rdma_ch *ch,
+ struct srpt_ioctx *ioctx)
+{
+ int max_lun_commands;
+ int req_lim_delta;
+
+ if (!atomic_read(&ch->supports_cred_req)) {
+ atomic_set(&ch->supports_cred_req, true);
+ PRINT_INFO("Enabled SRP_CRED_REQ support for session %s",
+ ch->sess_name);
+
+ max_lun_commands = scst_get_max_lun_commands(NULL, 0);
+ if (4 <= max_lun_commands && max_lun_commands < ch->rq_size) {
+ req_lim_delta = ch->rq_size - max_lun_commands;
+ PRINT_INFO("Decreasing initiator request limit from %d"
+ " to %d", ch->rq_size, max_lun_commands);
+ /*
+ * Note: at least in theory this may make the req_lim
+ * variable managed by the initiator temporarily
+ * negative.
+ */
+ ch->rq_size -= req_lim_delta;
+ atomic_sub(req_lim_delta, &ch->req_lim);
+ atomic_sub(req_lim_delta, &ch->req_lim_delta);
+ }
+ }
+}
+
+static u8 scst_to_srp_tsk_mgmt_status(const int scst_mgmt_status)
+{
+ switch (scst_mgmt_status) {
+ case SCST_MGMT_STATUS_SUCCESS:
+ return SRP_TSK_MGMT_SUCCESS;
+ case SCST_MGMT_STATUS_FN_NOT_SUPPORTED:
+ return SRP_TSK_MGMT_FUNC_NOT_SUPP;
+ case SCST_MGMT_STATUS_TASK_NOT_EXIST:
+ case SCST_MGMT_STATUS_LUN_NOT_EXIST:
+ case SCST_MGMT_STATUS_REJECTED:
+ case SCST_MGMT_STATUS_FAILED:
+ default:
+ break;
+ }
+ return SRP_TSK_MGMT_FAILED;
+}
+
+/**
+ * srpt_handle_new_iu() - Process a newly received information unit.
+ * @ch: RDMA channel through which the information unit has been received.
+ * @ioctx: SRPT I/O context associated with the information unit.
+ */
+static void srpt_handle_new_iu(struct srpt_rdma_ch *ch,
+ struct srpt_ioctx *ioctx,
+ enum scst_exec_context context)
+{
+ struct srp_cmd *srp_cmd;
+ struct scst_cmd *scmnd;
+ enum rdma_ch_state ch_state;
+ u8 srp_response_status;
+ int tsk_mgmt_status;
+ int len;
+ int send_rsp_res;
+
+ ch_state = atomic_read(&ch->state);
+ if (ch_state == RDMA_CHANNEL_CONNECTING) {
+ list_add_tail(&ioctx->wait_list, &ch->cmd_wait_list);
+ return;
+ }
+
+ ioctx->n_rbuf = 0;
+ ioctx->rbufs = NULL;
+ ioctx->n_rdma = 0;
+ ioctx->n_rdma_ius = 0;
+ ioctx->rdma_ius = NULL;
+ ioctx->mapped_sg_count = 0;
+ ioctx->scmnd = NULL;
+ ioctx->ch = ch;
+ atomic_set(&ioctx->state, SRPT_STATE_NEW);
+
+ if (unlikely(ch_state == RDMA_CHANNEL_DISCONNECTING)) {
+ srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
+ srpt_reset_ioctx(ch, ioctx, 0);
+ return;
+ }
+
+ WARN_ON(ch_state != RDMA_CHANNEL_LIVE);
+
+ scmnd = NULL;
+
+ srp_response_status = SAM_STAT_BUSY;
+ /* To keep the compiler happy. */
+ tsk_mgmt_status = SCST_MGMT_STATUS_FAILED;
+
+ ib_dma_sync_single_for_cpu(ch->sport->sdev->device,
+ ioctx->dma, srp_max_message_size,
+ DMA_FROM_DEVICE);
+
+ srp_cmd = ioctx->buf;
+
+ if (srp_cmd->opcode == SRP_CMD || srp_cmd->opcode == SRP_TSK_MGMT
+ || srp_cmd->opcode == SRP_I_LOGOUT) {
+ int req_lim;
+
+ req_lim = atomic_dec_return(&ch->req_lim);
+ if (unlikely(req_lim < 0))
+ PRINT_ERROR("req_lim = %d < 0", req_lim);
+ }
+
+ switch (srp_cmd->opcode) {
+ case SRP_CMD:
+ if (srpt_handle_cmd(ch, ioctx, context) < 0) {
+ scmnd = ioctx->scmnd;
+ if (scmnd)
+ srp_response_status =
+ scst_cmd_get_status(scmnd);
+ goto err;
+ }
+ break;
+
+ case SRP_TSK_MGMT:
+ tsk_mgmt_status = srpt_handle_tsk_mgmt(ch, ioctx);
+ if (tsk_mgmt_status != SCST_MGMT_STATUS_SUCCESS)
+ goto err;
+ break;
+
+ case SRP_I_LOGOUT:
+ goto err;
+
+ case SRP_CRED_RSP:
+ TRACE_DBG("%s", "received SRP_CRED_RSP");
+ srpt_handle_cred_rsp(ch, ioctx);
+ srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
+ srpt_reset_ioctx(ch, ioctx, 0);
+ break;
+
+ case SRP_AER_RSP:
+ TRACE_DBG("%s", "received SRP_AER_RSP");
+ srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
+ srpt_reset_ioctx(ch, ioctx, 0);
+ break;
+
+ case SRP_RSP:
+ default:
+ PRINT_ERROR("received IU with unknown opcode 0x%x",
+ srp_cmd->opcode);
+ srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
+ srpt_reset_ioctx(ch, ioctx, 0);
+ break;
+ }
+
+ return;
+
+err:
+ send_rsp_res = -ENOTCONN;
+
+ if (atomic_read(&ch->state) != RDMA_CHANNEL_LIVE) {
+ /* Give up if another thread modified the channel state. */
+ PRINT_ERROR("%s", "channel is no longer in connected state.");
+ } else {
+ s32 req_lim_delta;
+
+ req_lim_delta = srpt_req_lim_delta(ch);
+ if (srp_cmd->opcode == SRP_TSK_MGMT)
+ len = srpt_build_tskmgmt_rsp(ch, ioctx, req_lim_delta,
+ scst_to_srp_tsk_mgmt_status(tsk_mgmt_status),
+ ((struct srp_tsk_mgmt *)srp_cmd)->tag);
+ else if (scmnd)
+ len = srpt_build_cmd_rsp(ch, ioctx, req_lim_delta,
+ srp_cmd->tag, srp_response_status,
+ scst_cmd_get_sense_buffer(scmnd),
+ scst_cmd_get_sense_buffer_len(scmnd));
+ else
+ len = srpt_build_cmd_rsp(ch, ioctx, srp_cmd->tag,
+ req_lim_delta,
+ srp_response_status,
+ NULL, 0);
+ srpt_set_cmd_state(ioctx,
+ srp_cmd->opcode == SRP_TSK_MGMT
+ ? SRPT_STATE_MGMT_RSP_SENT
+ : SRPT_STATE_CMD_RSP_SENT);
+ send_rsp_res = srpt_post_send(ch, ioctx, len);
+ if (send_rsp_res) {
+ PRINT_ERROR("%s", "Sending SRP_RSP response failed.");
+ srpt_undo_req_lim_delta(ch, req_lim_delta - 1);
+ }
+ }
+ if (send_rsp_res) {
+ if (scmnd)
+ srpt_abort_scst_cmd(ioctx, context);
+ else {
+ srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
+ srpt_reset_ioctx(ch, ioctx, 1);
+ }
+ }
+}
+
+static void srpt_process_rcv_completion(struct ib_cq *cq,
+ struct srpt_rdma_ch *ch,
+ enum scst_exec_context context,
+ struct ib_wc *wc)
+{
+ struct srpt_device *sdev = ch->sport->sdev;
+ struct srpt_ioctx *ioctx;
+
+ EXTRACHECKS_WARN_ON((wc->wr_id & SRPT_OP_RECV) == 0);
+ EXTRACHECKS_WARN_ON((wc->wr_id & SRPT_OP_TTI) != 0);
+
+ if (wc->status == IB_WC_SUCCESS) {
+ ioctx = sdev->ioctx_ring[wc->wr_id & ~SRPT_OP_RECV];
+ srpt_handle_new_iu(ch, ioctx, context);
+ } else {
+ PRINT_INFO("receiving wr_id %u failed with status %d",
+ (unsigned)(wc->wr_id & ~SRPT_OP_RECV), wc->status);
+ }
+}
+
+static void srpt_process_send_completion(struct ib_cq *cq,
+ struct srpt_rdma_ch *ch,
+ enum scst_exec_context context,
+ struct ib_wc *wc)
+{
+ struct srpt_device *sdev = ch->sport->sdev;
+ struct srpt_ioctx *ioctx;
+
+ EXTRACHECKS_WARN_ON((wc->wr_id & SRPT_OP_RECV) != 0);
+
+ if (wc->status == IB_WC_SUCCESS) {
+ if ((wc->wr_id & SRPT_OP_TTI) == 0) {
+ ioctx = sdev->ioctx_ring[wc->wr_id];
+ if (wc->opcode == IB_WC_SEND)
+ srpt_handle_send_comp(ch, ioctx, context);
+ else {
+ EXTRACHECKS_WARN_ON(wc->opcode
+ != IB_WC_RDMA_READ);
+ srpt_handle_rdma_comp(ch, ioctx, context);
+ }
+ } else
+ srpt_put_tti_ioctx(ch);
+ } else {
+ PRINT_INFO("sending %s for wr_id %u failed with status %d",
+ wc->wr_id & SRPT_OP_TTI ? "request" : "response",
+ (unsigned)(wc->wr_id & ~SRPT_OP_FLAGS), wc->status);
+ srpt_handle_send_err_comp(ch, wc->wr_id, context);
+ }
+}
+
+static void srpt_process_completion(struct ib_cq *cq,
+ struct srpt_rdma_ch *ch,
+ enum scst_exec_context context)
+{
+ struct ib_wc wc[16];
+ int i, n;
+
+ EXTRACHECKS_WARN_ON(cq != ch->cq);
+
+ ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
+ while ((n = ib_poll_cq(cq, ARRAY_SIZE(wc), wc)) > 0) {
+ for (i = 0; i < n; i++) {
+ if (wc[i].wr_id & SRPT_OP_RECV)
+ srpt_process_rcv_completion(cq, ch, context,
+ &wc[i]);
+ else
+ srpt_process_send_completion(cq, ch, context,
+ &wc[i]);
+ }
+ }
+}
+
+/**
+ * srpt_completion() - IB completion queue callback function.
+ *
+ * Notes:
+ * - It is guaranteed that a completion handler will never be invoked
+ * concurrently on two different CPUs for the same completion queue. See also
+ * Documentation/infiniband/core_locking.txt and the implementation of
+ * handle_edge_irq() in kernel/irq/chip.c.
+ * - When threaded IRQs are enabled, completion handlers are invoked in thread
+ * context instead of interrupt context.
+ */
+static void srpt_completion(struct ib_cq *cq, void *ctx)
+{
+ struct srpt_rdma_ch *ch = ctx;
+
+ atomic_inc(&ch->processing_compl);
+ switch (thread) {
+ case MODE_IB_COMPLETION_IN_THREAD:
+ wake_up_interruptible(&ch->wait_queue);
+ break;
+ case MODE_IB_COMPLETION_IN_SIRQ:
+ srpt_process_completion(cq, ch, SCST_CONTEXT_THREAD);
+ break;
+ case MODE_ALL_IN_SIRQ:
+ srpt_process_completion(cq, ch, SCST_CONTEXT_TASKLET);
+ break;
+ }
+ atomic_dec(&ch->processing_compl);
+}
+
+static int srpt_compl_thread(void *arg)
+{
+ struct srpt_rdma_ch *ch;
+
+ /* Hibernation / freezing of the SRPT kernel thread is not supported. */
+ current->flags |= PF_NOFREEZE;
+
+ ch = arg;
+ BUG_ON(!ch);
+ PRINT_INFO("Session %s: kernel thread %s (PID %d) started",
+ ch->sess_name, ch->thread->comm, current->pid);
+ while (!kthread_should_stop()) {
+ wait_event_interruptible(ch->wait_queue,
+ (srpt_process_completion(ch->cq, ch,
+ SCST_CONTEXT_THREAD),
+ kthread_should_stop()));
+ }
+ PRINT_INFO("Session %s: kernel thread %s (PID %d) stopped",
+ ch->sess_name, ch->thread->comm, current->pid);
+ return 0;
+}
+
+/**
+ * srpt_create_ch_ib() - Create receive and send completion queues.
+ */
+static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
+{
+ struct ib_qp_init_attr *qp_init;
+ struct srpt_device *sdev = ch->sport->sdev;
+ int ret;
+
+ EXTRACHECKS_WARN_ON(ch->rq_size < 1);
+
+ ret = -ENOMEM;
+ qp_init = kzalloc(sizeof *qp_init, GFP_KERNEL);
+ if (!qp_init)
+ goto out;
+
+ ch->cq = ib_create_cq(sdev->device, srpt_completion, NULL, ch,
+ ch->rq_size + srpt_sq_size, 0);
+ if (IS_ERR(ch->cq)) {
+ ret = PTR_ERR(ch->cq);
+ PRINT_ERROR("failed to create CQ cqe= %d ret= %d",
+ ch->rq_size + srpt_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->srq = sdev->srq;
+ qp_init->sq_sig_type = IB_SIGNAL_REQ_WR;
+ qp_init->qp_type = IB_QPT_RC;
+ qp_init->cap.max_send_wr = srpt_sq_size;
+ qp_init->cap.max_send_sge = SRPT_DEF_SG_PER_WQE;
+
+ ch->qp = ib_create_qp(sdev->pd, qp_init);
+ if (IS_ERR(ch->qp)) {
+ ret = PTR_ERR(ch->qp);
+ PRINT_ERROR("failed to create_qp ret= %d", ret);
+ goto err_destroy_cq;
+ }
+
+ atomic_set(&ch->sq_wr_avail, qp_init->cap.max_send_wr);
+
+ TRACE_DBG("%s: max_cqe= %d max_sge= %d sq_size = %d"
+ " cm_id= %p", __func__, ch->cq->cqe,
+ qp_init->cap.max_send_sge, qp_init->cap.max_send_wr,
+ ch->cm_id);
+
+ ret = srpt_init_ch_qp(ch, ch->qp);
+ if (ret)
+ goto err_destroy_qp;
+
+ if (thread == MODE_IB_COMPLETION_IN_THREAD) {
+ init_waitqueue_head(&ch->wait_queue);
+
+ TRACE_DBG("creating IB completion thread for session %s",
+ ch->sess_name);
+
+ ch->thread = kthread_run(srpt_compl_thread, ch,
+ "ib_srpt_compl");
+ if (IS_ERR(ch->thread)) {
+ PRINT_ERROR("failed to create kernel thread %ld",
+ PTR_ERR(ch->thread));
+ ch->thread = NULL;
+ goto err_destroy_qp;
+ }
+ } else
+ ib_req_notify_cq(ch->cq, IB_CQ_NEXT_COMP);
+
+out:
+ kfree(qp_init);
+ return ret;
+
+err_destroy_qp:
+ ib_destroy_qp(ch->qp);
+err_destroy_cq:
+ ib_destroy_cq(ch->cq);
+ goto out;
+}
+
+static void srpt_destroy_ch_ib(struct srpt_rdma_ch *ch)
+{
+ struct ib_qp_attr qp_attr;
+ int ret;
+
+ if (ch->thread)
+ kthread_stop(ch->thread);
+
+ qp_attr.qp_state = IB_QPS_RESET;
+ ret = ib_modify_qp(ch->qp, &qp_attr, IB_QP_STATE);
+ if (ret < 0)
+ PRINT_ERROR("Resetting queue pair state failed: %d", ret);
+
+ while (atomic_read(&ch->processing_compl))
+ ;
+
+ ib_destroy_qp(ch->qp);
+ ib_destroy_cq(ch->cq);
+}
+
+/**
+ * srpt_unregister_channel() - Start RDMA channel disconnection.
+ *
+ * Note: The caller must hold ch->sdev->spinlock.
+ */
+static void srpt_unregister_channel(struct srpt_rdma_ch *ch)
+ __acquires(&ch->sport->sdev->spinlock)
+ __releases(&ch->sport->sdev->spinlock)
+{
+ struct srpt_device *sdev;
+
+ sdev = ch->sport->sdev;
+ list_del(&ch->list);
+ atomic_set(&ch->state, RDMA_CHANNEL_DISCONNECTING);
+ spin_unlock_irq(&sdev->spinlock);
+
+ /*
+ * At this point it is guaranteed that no new commands will be sent to
+ * the SCST core for channel ch, which is a requirement for
+ * scst_unregister_session().
+ */
+
+ TRACE_DBG("unregistering session %p", ch->scst_sess);
+ scst_unregister_session(ch->scst_sess, 0, srpt_release_channel);
+ spin_lock_irq(&sdev->spinlock);
+}
+
+/**
+ * srpt_release_channel_by_cmid() - Release a channel.
+ * @cm_id: Pointer to the CM ID of the channel to be released.
+ *
+ * Note: Must be called from inside srpt_cm_handler to avoid a race between
+ * accessing sdev->spinlock and the call to kfree(sdev) in srpt_remove_one()
+ * (the caller of srpt_cm_handler holds the cm_id spinlock; srpt_remove_one()
+ * waits until all SCST sessions for the associated IB device have been
+ * unregistered and SCST session registration involves a call to
+ * ib_destroy_cm_id(), which locks the cm_id spinlock and hence waits until
+ * this function has finished).
+ */
+static void srpt_release_channel_by_cmid(struct ib_cm_id *cm_id)
+{
+ struct srpt_device *sdev;
+ struct srpt_rdma_ch *ch;
+
+ EXTRACHECKS_WARN_ON_ONCE(irqs_disabled());
+
+ sdev = cm_id->context;
+ BUG_ON(!sdev);
+ spin_lock_irq(&sdev->spinlock);
+ list_for_each_entry(ch, &sdev->rch_list, list) {
+ if (ch->cm_id == cm_id) {
+ srpt_unregister_channel(ch);
+ break;
+ }
+ }
+ spin_unlock_irq(&sdev->spinlock);
+}
+
+/**
+ * srpt_find_channel() - Look up an RDMA channel.
+ * @cm_id: Pointer to the CM ID of the channel to be looked up.
+ *
+ * Return NULL if no matching RDMA channel has been found.
+ */
+static struct srpt_rdma_ch *srpt_find_channel(struct srpt_device *sdev,
+ struct ib_cm_id *cm_id)
+{
+ struct srpt_rdma_ch *ch;
+ bool found;
+
+ EXTRACHECKS_WARN_ON_ONCE(irqs_disabled());
+ BUG_ON(!sdev);
+
+ found = false;
+ spin_lock_irq(&sdev->spinlock);
+ list_for_each_entry(ch, &sdev->rch_list, list) {
+ if (ch->cm_id == cm_id) {
+ found = true;
+ break;
+ }
+ }
+ spin_unlock_irq(&sdev->spinlock);
+
+ return found ? ch : NULL;
+}
+
+/**
+ * srpt_release_channel() - Release all resources associated with an RDMA channel.
+ *
+ * Notes:
+ * - The caller must have removed the channel from the channel list before
+ * calling this function.
+ * - Must be called as a callback function via scst_unregister_session(). Never
+ * call this function directly because doing so would trigger several race
+ * conditions.
+ * - Do not access ch->sport or ch->sport->sdev in this function because the
+ * memory that was allocated for the sport and/or sdev data structures may
+ * already have been freed at the time this function is called.
+ */
+static void srpt_release_channel(struct scst_session *scst_sess)
+{
+ struct srpt_rdma_ch *ch;
+
+ ch = scst_sess_get_tgt_priv(scst_sess);
+ BUG_ON(!ch);
+ WARN_ON(atomic_read(&ch->state) != RDMA_CHANNEL_DISCONNECTING);
+
+ TRACE_DBG("destroying cm_id %p", ch->cm_id);
+ BUG_ON(!ch->cm_id);
+ ib_destroy_cm_id(ch->cm_id);
+
+ srpt_destroy_ch_ib(ch);
+ srpt_free_tti_ioctx(ch);
+
+ kfree(ch);
+}
+
+/**
+ * srpt_enable_target() - Allows to enable a target via sysfs.
+ */
+static int srpt_enable_target(struct scst_tgt *scst_tgt, bool enable)
+{
+ struct srpt_device *sdev = scst_tgt_get_tgt_priv(scst_tgt);
+
+ EXTRACHECKS_WARN_ON_ONCE(irqs_disabled());
+
+ TRACE_DBG("%s target %s", enable ? "Enabling" : "Disabling",
+ sdev->device->name);
+
+ spin_lock_irq(&sdev->spinlock);
+ sdev->enabled = enable;
+ spin_unlock_irq(&sdev->spinlock);
+
+ return 0;
+}
+
+/**
+ * srpt_is_target_enabled() - Allows to query a targets status via sysfs.
+ */
+static bool srpt_is_target_enabled(struct scst_tgt *scst_tgt)
+{
+ struct srpt_device *sdev = scst_tgt_get_tgt_priv(scst_tgt);
+ bool res;
+
+ EXTRACHECKS_WARN_ON_ONCE(irqs_disabled());
+
+ spin_lock_irq(&sdev->spinlock);
+ res = sdev->enabled;
+ spin_unlock_irq(&sdev->spinlock);
+ return res;
+}
+
+/**
+ * srpt_cm_req_recv() - Process the event IB_CM_REQ_RECEIVED.
+ *
+ * Ownership of the cm_id is transferred to the SCST session if this functions
+ * returns zero. Otherwise the caller remains the owner of cm_id.
+ */
+static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
+ struct ib_cm_req_event_param *param,
+ void *private_data)
+{
+ struct srpt_device *sdev = cm_id->context;
+ struct srp_login_req *req;
+ struct srp_login_rsp *rsp;
+ struct srp_login_rej *rej;
+ struct ib_cm_rep_param *rep_param;
+ struct srpt_rdma_ch *ch, *tmp_ch;
+ u32 it_iu_len;
+ int ret = 0;
+
+ EXTRACHECKS_WARN_ON_ONCE(irqs_disabled());
+
+ if (WARN_ON(!sdev || !private_data))
+ return -EINVAL;
+
+ req = (struct srp_login_req *)private_data;
+
+ it_iu_len = be32_to_cpu(req->req_it_iu_len);
+
+ PRINT_INFO("Received SRP_LOGIN_REQ with"
+ " i_port_id 0x%llx:0x%llx, t_port_id 0x%llx:0x%llx and it_iu_len %d"
+ " on port %d (guid=0x%llx:0x%llx)",
+ be64_to_cpu(*(__be64 *)&req->initiator_port_id[0]),
+ be64_to_cpu(*(__be64 *)&req->initiator_port_id[8]),
+ be64_to_cpu(*(__be64 *)&req->target_port_id[0]),
+ be64_to_cpu(*(__be64 *)&req->target_port_id[8]),
+ it_iu_len,
+ param->port,
+ be64_to_cpu(*(__be64 *)&sdev->port[param->port - 1].gid.raw[0]),
+ be64_to_cpu(*(__be64 *)&sdev->port[param->port - 1].gid.raw[8]));
+
+ 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) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (it_iu_len > srp_max_message_size || it_iu_len < 64) {
+ rej->reason = __constant_cpu_to_be32(
+ SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE);
+ ret = -EINVAL;
+ PRINT_ERROR("rejected SRP_LOGIN_REQ because its"
+ " length (%d bytes) is out of range (%d .. %d)",
+ it_iu_len, 64, srp_max_message_size);
+ goto reject;
+ }
+
+ if (!srpt_is_target_enabled(sdev->scst_tgt)) {
+ rej->reason = __constant_cpu_to_be32(
+ SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
+ ret = -EINVAL;
+ PRINT_ERROR("rejected SRP_LOGIN_REQ because the target %s"
+ " has not yet been enabled", sdev->device->name);
+ goto reject;
+ }
+
+ if ((req->req_flags & SRP_MTCH_ACTION) == SRP_MULTICHAN_SINGLE) {
+ rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_NO_CHAN;
+
+ spin_lock_irq(&sdev->spinlock);
+
+ list_for_each_entry_safe(ch, tmp_ch, &sdev->rch_list, list) {
+ if (!memcmp(ch->i_port_id, req->initiator_port_id, 16)
+ && !memcmp(ch->t_port_id, req->target_port_id, 16)
+ && param->port == ch->sport->port
+ && param->listen_id == ch->sport->sdev->cm_id
+ && ch->cm_id) {
+ enum rdma_ch_state prev_state;
+
+ /* found an existing channel */
+ TRACE_DBG("Found existing channel name= %s"
+ " cm_id= %p state= %d",
+ ch->sess_name, ch->cm_id,
+ atomic_read(&ch->state));
+
+ prev_state = atomic_xchg(&ch->state,
+ RDMA_CHANNEL_DISCONNECTING);
+ if (prev_state == RDMA_CHANNEL_CONNECTING)
+ srpt_unregister_channel(ch);
+
+ spin_unlock_irq(&sdev->spinlock);
+
+ rsp->rsp_flags =
+ SRP_LOGIN_RSP_MULTICHAN_TERMINATED;
+
+ if (prev_state == RDMA_CHANNEL_LIVE) {
+ ib_send_cm_dreq(ch->cm_id, NULL, 0);
+ PRINT_INFO("disconnected"
+ " session %s because a new"
+ " SRP_LOGIN_REQ has been received.",
+ ch->sess_name);
+ } else if (prev_state ==
+ RDMA_CHANNEL_CONNECTING) {
+ PRINT_ERROR("%s", "rejected"
+ " SRP_LOGIN_REQ because another login"
+ " request is being processed.");
+ ib_send_cm_rej(ch->cm_id,
+ IB_CM_REJ_NO_RESOURCES,
+ NULL, 0, NULL, 0);
+ }
+
+ spin_lock_irq(&sdev->spinlock);
+ }
+ }
+
+ spin_unlock_irq(&sdev->spinlock);
+
+ } else
+ rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_MAINTAINED;
+
+ 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 = __constant_cpu_to_be32(
+ SRP_LOGIN_REJ_UNABLE_ASSOCIATE_CHANNEL);
+ ret = -ENOMEM;
+ PRINT_ERROR("%s", "rejected SRP_LOGIN_REQ because it"
+ " has an invalid target port identifier.");
+ goto reject;
+ }
+
+ ch = kzalloc(sizeof *ch, GFP_KERNEL);
+ if (!ch) {
+ rej->reason = __constant_cpu_to_be32(
+ SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
+ PRINT_ERROR("%s",
+ "rejected SRP_LOGIN_REQ because out of memory.");
+ ret = -ENOMEM;
+ goto reject;
+ }
+
+ memcpy(ch->i_port_id, req->initiator_port_id, 16);
+ memcpy(ch->t_port_id, req->target_port_id, 16);
+ ch->sport = &sdev->port[param->port - 1];
+ ch->cm_id = cm_id;
+ ch->rq_size = max(SRPT_RQ_SIZE, scst_get_max_lun_commands(NULL, 0));
+ atomic_set(&ch->processing_compl, 0);
+ atomic_set(&ch->state, RDMA_CHANNEL_CONNECTING);
+ INIT_LIST_HEAD(&ch->cmd_wait_list);
+
+ ch->tti_head = 0;
+ ch->tti_tail = 0;
+ ret = srpt_alloc_tti_ioctx(ch);
+ if (ret) {
+ PRINT_ERROR("%s", "send ring allocation failed");
+ goto free_ch;
+ }
+
+ ret = srpt_create_ch_ib(ch);
+ if (ret) {
+ rej->reason = __constant_cpu_to_be32(
+ SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
+ PRINT_ERROR("%s", "rejected SRP_LOGIN_REQ because creating"
+ " a new RDMA channel failed.");
+ goto free_req_ring;
+ }
+
+ ret = srpt_ch_qp_rtr(ch, ch->qp);
+ if (ret) {
+ rej->reason = __constant_cpu_to_be32(
+ SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
+ PRINT_ERROR("rejected SRP_LOGIN_REQ because enabling"
+ " RTR failed (error code = %d)", ret);
+ goto destroy_ib;
+ }
+
+ if (use_port_guid_in_session_name) {
+ /*
+ * If the kernel module parameter use_port_guid_in_session_name
+ * has been specified, use a combination of the target port
+ * GUID and the initiator port ID as the session name. This
+ * was the original behavior of the SRP target implementation
+ * (i.e. before the SRPT was included in OFED 1.3).
+ */
+ snprintf(ch->sess_name, sizeof(ch->sess_name),
+ "0x%016llx%016llx",
+ be64_to_cpu(*(__be64 *)
+ &sdev->port[param->port - 1].gid.raw[8]),
+ be64_to_cpu(*(__be64 *)(ch->i_port_id + 8)));
+ } else {
+ /*
+ * Default behavior: use the initator port identifier as the
+ * session name.
+ */
+ snprintf(ch->sess_name, sizeof(ch->sess_name),
+ "0x%016llx%016llx",
+ be64_to_cpu(*(__be64 *)ch->i_port_id),
+ be64_to_cpu(*(__be64 *)(ch->i_port_id + 8)));
+ }
+
+ TRACE_DBG("registering session %s", ch->sess_name);
+
+ BUG_ON(!sdev->scst_tgt);
+ ch->scst_sess = scst_register_session(sdev->scst_tgt, 0, ch->sess_name,
+ ch, NULL, NULL);
+ if (!ch->scst_sess) {
+ rej->reason = __constant_cpu_to_be32(
+ SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
+ TRACE_DBG("%s", "Failed to create SCST session");
+ goto release_channel;
+ }
+
+ TRACE_DBG("Establish connection sess=%p name=%s cm_id=%p",
+ ch->scst_sess, ch->sess_name, ch->cm_id);
+
+ /* create srp_login_response */
+ rsp->opcode = SRP_LOGIN_RSP;
+ rsp->tag = req->tag;
+ rsp->max_it_iu_len = req->req_it_iu_len;
+ rsp->max_ti_iu_len = req->req_it_iu_len;
+ ch->max_ti_iu_len = it_iu_len;
+ atomic_set(&ch->supports_cred_req, false);
+ rsp->buf_fmt = __constant_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);
+ atomic_set(&ch->req_lim_waiter_count, 0);
+ init_completion(&ch->req_lim_compl);
+
+ /* create cm reply */
+ rep_param->qp_num = ch->qp->qp_num;
+ rep_param->private_data = (void *)rsp;
+ rep_param->private_data_len = sizeof *rsp;
+ rep_param->rnr_retry_count = 7;
+ rep_param->flow_control = 1;
+ rep_param->failover_accepted = 0;
+ rep_param->srq = 1;
+ rep_param->responder_resources = 4;
+ rep_param->initiator_depth = 4;
+
+ ret = ib_send_cm_rep(cm_id, rep_param);
+ if (ret) {
+ PRINT_ERROR("sending SRP_LOGIN_REQ response failed"
+ " (error code = %d)", ret);
+ goto release_channel;
+ }
+
+ spin_lock_irq(&sdev->spinlock);
+ list_add_tail(&ch->list, &sdev->rch_list);
+ spin_unlock_irq(&sdev->spinlock);
+
+ goto out;
+
+release_channel:
+ atomic_set(&ch->state, RDMA_CHANNEL_DISCONNECTING);
+ scst_unregister_session(ch->scst_sess, 0, NULL);
+ ch->scst_sess = NULL;
+
+destroy_ib:
+ srpt_destroy_ch_ib(ch);
+
+free_req_ring:
+ srpt_free_tti_ioctx(ch);
+
+free_ch:
+ kfree(ch);
+
+reject:
+ rej->opcode = SRP_LOGIN_REJ;
+ rej->tag = req->tag;
+ rej->buf_fmt = __constant_cpu_to_be16(SRP_BUF_FORMAT_DIRECT
+ | SRP_BUF_FORMAT_INDIRECT);
+
+ ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED, NULL, 0,
+ (void *)rej, sizeof *rej);
+
+out:
+ kfree(rep_param);
+ kfree(rsp);
+ kfree(rej);
+
+ return ret;
+}
+
+static void srpt_cm_rej_recv(struct ib_cm_id *cm_id)
+{
+ PRINT_INFO("Received InfiniBand REJ packet for cm_id %p.", cm_id);
+ srpt_release_channel_by_cmid(cm_id);
+}
+
+/**
+ * srpt_cm_rtu_recv() - Process an IB_CM_RTU_RECEIVED or IB_CM_USER_ESTABLISHED event.
+ *
+ * An IB_CM_RTU_RECEIVED message indicates that the connection is established
+ * and that the recipient may begin transmitting (RTU = ready to use).
+ */
+static void srpt_cm_rtu_recv(struct ib_cm_id *cm_id)
+{
+ struct srpt_rdma_ch *ch;
+ int ret;
+
+ ch = srpt_find_channel(cm_id->context, cm_id);
+ WARN_ON(!ch);
+ if (!ch)
+ goto out;
+
+ if (srpt_test_and_set_channel_state(ch, RDMA_CHANNEL_CONNECTING,
+ RDMA_CHANNEL_LIVE) == RDMA_CHANNEL_CONNECTING) {
+ struct srpt_ioctx *ioctx, *ioctx_tmp;
+
+ ret = srpt_ch_qp_rts(ch, ch->qp);
+
+ if (srpt_autodetect_cred_req)
+ srpt_send_cred_req(ch, 0);
+
+ list_for_each_entry_safe(ioctx, ioctx_tmp, &ch->cmd_wait_list,
+ wait_list) {
+ list_del(&ioctx->wait_list);
+ srpt_handle_new_iu(ch, ioctx, SCST_CONTEXT_THREAD);
+ }
+ if (ret && srpt_test_and_set_channel_state(ch,
+ RDMA_CHANNEL_LIVE,
+ RDMA_CHANNEL_DISCONNECTING) == RDMA_CHANNEL_LIVE) {
+ TRACE_DBG("cm_id=%p sess_name=%s state=%d",
+ cm_id, ch->sess_name,
+ atomic_read(&ch->state));
+ ib_send_cm_dreq(ch->cm_id, NULL, 0);
+ }
+ }
+
+out:
+ ;
+}
+
+static void srpt_cm_timewait_exit(struct ib_cm_id *cm_id)
+{
+ PRINT_INFO("Received InfiniBand TimeWait exit for cm_id %p.", cm_id);
+ srpt_release_channel_by_cmid(cm_id);
+}
+
+static void srpt_cm_rep_error(struct ib_cm_id *cm_id)
+{
+ PRINT_INFO("Received InfiniBand REP error for cm_id %p.", cm_id);
+ srpt_release_channel_by_cmid(cm_id);
+}
+
+/**
+ * srpt_cm_dreq_recv() - Process reception of a DREQ message.
+ */
+static void srpt_cm_dreq_recv(struct ib_cm_id *cm_id)
+{
+ struct srpt_rdma_ch *ch;
+
+ ch = srpt_find_channel(cm_id->context, cm_id);
+ if (!ch) {
+ TRACE_DBG("Received DREQ for channel %p which is already"
+ " being unregistered.", cm_id);
+ goto out;
+ }
+
+ TRACE_DBG("cm_id= %p ch->state= %d", cm_id, atomic_read(&ch->state));
+
+ switch (atomic_read(&ch->state)) {
+ case RDMA_CHANNEL_LIVE:
+ case RDMA_CHANNEL_CONNECTING:
+ ib_send_cm_drep(ch->cm_id, NULL, 0);
+ PRINT_INFO("Received DREQ and sent DREP for session %s.",
+ ch->sess_name);
+ break;
+ case RDMA_CHANNEL_DISCONNECTING:
+ default:
+ break;
+ }
+
+out:
+ ;
+}
+
+/**
+ * srpt_cm_drep_recv() - Process reception of a DREP message.
+ */
+static void srpt_cm_drep_recv(struct ib_cm_id *cm_id)
+{
+ PRINT_INFO("Received InfiniBand DREP message for cm_id %p.", cm_id);
+ srpt_release_channel_by_cmid(cm_id);
+}
+
+/**
+ * srpt_cm_handler() - IB connection manager callback function.
+ *
+ * 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, struct ib_cm_event *event)
+{
+ int ret;
+
+ ret = 0;
+ switch (event->event) {
+ case IB_CM_REQ_RECEIVED:
+ ret = srpt_cm_req_recv(cm_id, &event->param.req_rcvd,
+ event->private_data);
+ break;
+ case IB_CM_REJ_RECEIVED:
+ srpt_cm_rej_recv(cm_id);
+ break;
+ case IB_CM_RTU_RECEIVED:
+ case IB_CM_USER_ESTABLISHED:
+ srpt_cm_rtu_recv(cm_id);
+ break;
+ case IB_CM_DREQ_RECEIVED:
+ srpt_cm_dreq_recv(cm_id);
+ break;
+ case IB_CM_DREP_RECEIVED:
+ srpt_cm_drep_recv(cm_id);
+ break;
+ case IB_CM_TIMEWAIT_EXIT:
+ srpt_cm_timewait_exit(cm_id);
+ break;
+ case IB_CM_REP_ERROR:
+ srpt_cm_rep_error(cm_id);
+ break;
+ case IB_CM_DREQ_ERROR:
+ PRINT_INFO("%s", "Received IB DREQ ERROR event.");
+ break;
+ case IB_CM_MRA_RECEIVED:
+ PRINT_INFO("%s", "Received IB MRA event");
+ break;
+ default:
+ PRINT_ERROR("received unrecognized IB CM event %d",
+ event->event);
+ break;
+ }
+
+ return ret;
+}
+
+/**
+ * srpt_map_sg_to_ib_sge() - Map an SG list to an IB SGE list.
+ */
+static int srpt_map_sg_to_ib_sge(struct srpt_rdma_ch *ch,
+ struct srpt_ioctx *ioctx,
+ struct scst_cmd *scmnd)
+{
+ struct scatterlist *sg;
+ int sg_cnt;
+ scst_data_direction dir;
+ struct rdma_iu *riu;
+ struct srp_direct_buf *db;
+ dma_addr_t dma_addr;
+ struct ib_sge *sge;
+ u64 raddr;
+ u32 rsize;
+ u32 tsize;
+ u32 dma_len;
+ int count, nrdma;
+ int i, j, k;
+
+ BUG_ON(!ch);
+ BUG_ON(!ioctx);
+ BUG_ON(!scmnd);
+ dir = scst_cmd_get_data_direction(scmnd);
+ BUG_ON(dir == SCST_DATA_NONE);
+ /*
+ * Cache 'dir' because it is needed in srpt_unmap_sg_to_ib_sge()
+ * and because scst_set_cmd_error_status() resets scmnd->data_direction.
+ */
+ ioctx->dir = dir;
+ if (dir == SCST_DATA_WRITE) {
+ scst_cmd_get_write_fields(scmnd, &sg, &sg_cnt);
+ WARN_ON(!sg);
+ } else {
+ sg = scst_cmd_get_sg(scmnd);
+ sg_cnt = scst_cmd_get_sg_cnt(scmnd);
+ WARN_ON(!sg);
+ }
+ ioctx->sg = sg;
+ ioctx->sg_cnt = sg_cnt;
+ count = ib_dma_map_sg(ch->sport->sdev->device, sg, sg_cnt,
+ scst_to_tgt_dma_dir(dir));
+ if (unlikely(!count))
+ return -EBUSY;
+
+ ioctx->mapped_sg_count = count;
+
+ if (ioctx->rdma_ius && ioctx->n_rdma_ius)
+ nrdma = ioctx->n_rdma_ius;
+ else {
+ nrdma = count / SRPT_DEF_SG_PER_WQE + ioctx->n_rbuf;
+
+ ioctx->rdma_ius = kzalloc(nrdma * sizeof *riu,
+ scst_cmd_atomic(scmnd)
+ ? GFP_ATOMIC : GFP_KERNEL);
+ if (!ioctx->rdma_ius)
+ goto free_mem;
+
+ ioctx->n_rdma_ius = nrdma;
+ }
+
+ db = ioctx->rbufs;
+ tsize = (dir == SCST_DATA_READ)
+ ? scst_cmd_get_adjusted_resp_data_len(scmnd)
+ : scst_cmd_get_bufflen(scmnd);
+ dma_len = sg_dma_len(&sg[0]);
+ riu = ioctx->rdma_ius;
+
+ /*
+ * For each remote desc - calculate the #ib_sge.
+ * If #ib_sge < SRPT_DEF_SG_PER_WQE per rdma operation then
+ * each remote desc rdma_iu is required a rdma wr;
+ * else
+ * we need to allocate extra rdma_iu to carry extra #ib_sge in
+ * another rdma wr
+ */
+ for (i = 0, j = 0;
+ j < count && i < ioctx->n_rbuf && tsize > 0; ++i, ++riu, ++db) {
+ rsize = be32_to_cpu(db->len);
+ raddr = be64_to_cpu(db->va);
+ riu->raddr = raddr;
+ riu->rkey = be32_to_cpu(db->key);
+ riu->sge_cnt = 0;
+
+ /* calculate how many sge required for this remote_buf */
+ while (rsize > 0 && tsize > 0) {
+
+ if (rsize >= dma_len) {
+ tsize -= dma_len;
+ rsize -= dma_len;
+ raddr += dma_len;
+
+ if (tsize > 0) {
+ ++j;
+ if (j < count)
+ dma_len = sg_dma_len(&sg[j]);
+ }
+ } else {
+ tsize -= rsize;
+ dma_len -= rsize;
+ rsize = 0;
+ }
+
+ ++riu->sge_cnt;
+
+ if (rsize > 0 && riu->sge_cnt == SRPT_DEF_SG_PER_WQE) {
+ ++ioctx->n_rdma;
+ riu->sge =
+ kmalloc(riu->sge_cnt * sizeof *riu->sge,
+ scst_cmd_atomic(scmnd)
+ ? GFP_ATOMIC : GFP_KERNEL);
+ if (!riu->sge)
+ goto free_mem;
+
+ ++riu;
+ riu->sge_cnt = 0;
+ riu->raddr = raddr;
+ riu->rkey = be32_to_cpu(db->key);
+ }
+ }
+
+ ++ioctx->n_rdma;
+ riu->sge = kmalloc(riu->sge_cnt * sizeof *riu->sge,
+ scst_cmd_atomic(scmnd)
+ ? GFP_ATOMIC : GFP_KERNEL);
+ if (!riu->sge)
+ goto free_mem;
+ }
+
+ db = ioctx->rbufs;
+ tsize = (dir == SCST_DATA_READ)
+ ? scst_cmd_get_adjusted_resp_data_len(scmnd)
+ : scst_cmd_get_bufflen(scmnd);
+ riu = ioctx->rdma_ius;
+ dma_len = sg_dma_len(&sg[0]);
+ dma_addr = sg_dma_address(&sg[0]);
+
+ /* this second loop is really mapped sg_addres to rdma_iu->ib_sge */
+ for (i = 0, j = 0;
+ j < count && i < ioctx->n_rbuf && tsize > 0; ++i, ++riu, ++db) {
+ rsize = be32_to_cpu(db->len);
+ sge = riu->sge;
+ k = 0;
+
+ while (rsize > 0 && tsize > 0) {
+ sge->addr = dma_addr;
+ sge->lkey = ch->sport->sdev->mr->lkey;
+
+ if (rsize >= dma_len) {
+ sge->length =
+ (tsize < dma_len) ? tsize : dma_len;
+ tsize -= dma_len;
+ rsize -= dma_len;
+
+ if (tsize > 0) {
+ ++j;
+ if (j < count) {
+ dma_len = sg_dma_len(&sg[j]);
+ dma_addr =
+ sg_dma_address(&sg[j]);
+ }
+ }
+ } else {
+ sge->length = (tsize < rsize) ? tsize : rsize;
+ tsize -= rsize;
+ dma_len -= rsize;
+ dma_addr += rsize;
+ rsize = 0;
+ }
+
+ ++k;
+ if (k == riu->sge_cnt && rsize > 0) {
+ ++riu;
+ sge = riu->sge;
+ k = 0;
+ } else if (rsize > 0)
+ ++sge;
+ }
+ }
+
+ return 0;
+
+free_mem:
+ srpt_unmap_sg_to_ib_sge(ch, ioctx);
+
+ return -ENOMEM;
+}
+
+/**
+ * srpt_unmap_sg_to_ib_sge() - Unmap an IB SGE list.
+ */
+static void srpt_unmap_sg_to_ib_sge(struct srpt_rdma_ch *ch,
+ struct srpt_ioctx *ioctx)
+{
+ struct scst_cmd *scmnd;
+ struct scatterlist *sg;
+ scst_data_direction dir;
+
+ EXTRACHECKS_BUG_ON(!ch);
+ EXTRACHECKS_BUG_ON(!ioctx);
+ EXTRACHECKS_BUG_ON(ioctx->n_rdma && !ioctx->rdma_ius);
+
+ while (ioctx->n_rdma)
+ kfree(ioctx->rdma_ius[--ioctx->n_rdma].sge);
+
+ kfree(ioctx->rdma_ius);
+ ioctx->rdma_ius = NULL;
+
+ if (ioctx->mapped_sg_count) {
+ scmnd = ioctx->scmnd;
+ EXTRACHECKS_BUG_ON(!scmnd);
+ EXTRACHECKS_WARN_ON(ioctx->scmnd != scmnd);
+ EXTRACHECKS_WARN_ON(ioctx != scst_cmd_get_tgt_priv(scmnd));
+ sg = ioctx->sg;
+ EXTRACHECKS_WARN_ON(!sg);
+ dir = ioctx->dir;
+ EXTRACHECKS_BUG_ON(dir == SCST_DATA_NONE);
+ ib_dma_unmap_sg(ch->sport->sdev->device, sg, ioctx->sg_cnt,
+ scst_to_tgt_dma_dir(dir));
+ ioctx->mapped_sg_count = 0;
+ }
+}
+
+/**
+ * srpt_perform_rdmas() - Perform IB RDMA.
+ */
+static int srpt_perform_rdmas(struct srpt_rdma_ch *ch, struct srpt_ioctx *ioctx,
+ scst_data_direction dir)
+{
+ struct ib_send_wr wr;
+ struct ib_send_wr *bad_wr;
+ struct rdma_iu *riu;
+ int i;
+ int ret;
+ int sq_wr_avail;
+
+ if (dir == SCST_DATA_WRITE) {
+ ret = -ENOMEM;
+ sq_wr_avail = atomic_sub_return(ioctx->n_rdma,
+ &ch->sq_wr_avail);
+ if (sq_wr_avail < 0) {
+ atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
+ PRINT_ERROR("%s[%d]: send queue full",
+ __func__, __LINE__);
+ goto out;
+ }
+ }
+
+ ret = 0;
+ riu = ioctx->rdma_ius;
+ memset(&wr, 0, sizeof wr);
+
+ for (i = 0; i < ioctx->n_rdma; ++i, ++riu) {
+ wr.opcode = (dir == SCST_DATA_READ) ?
+ IB_WR_RDMA_WRITE : IB_WR_RDMA_READ;
+ wr.next = NULL;
+ wr.wr_id = ioctx->index;
+ wr.wr.rdma.remote_addr = riu->raddr;
+ wr.wr.rdma.rkey = riu->rkey;
+ wr.num_sge = riu->sge_cnt;
+ wr.sg_list = riu->sge;
+
+ /* only get completion event for the last rdma wr */
+ if (i == (ioctx->n_rdma - 1) && dir == SCST_DATA_WRITE)
+ wr.send_flags = IB_SEND_SIGNALED;
+
+ ret = ib_post_send(ch->qp, &wr, &bad_wr);
+ if (ret)
+ goto out;
+ }
+
+out:
+ return ret;
+}
+
+/**
+ * srpt_xfer_data() - Start data transfer from initiator to target.
+ *
+ * Note: Must not block.
+ */
+static int srpt_xfer_data(struct srpt_rdma_ch *ch, struct srpt_ioctx *ioctx,
+ struct scst_cmd *scmnd)
+{
+ int ret;
+
+ ret = srpt_map_sg_to_ib_sge(ch, ioctx, scmnd);
+ if (ret) {
+ PRINT_ERROR("%s[%d] ret=%d", __func__, __LINE__, ret);
+ ret = SCST_TGT_RES_QUEUE_FULL;
+ goto out;
+ }
+
+ ret = srpt_perform_rdmas(ch, ioctx, scst_cmd_get_data_direction(scmnd));
+ if (ret) {
+ if (ret == -EAGAIN || ret == -ENOMEM) {
+ PRINT_INFO("%s[%d] queue full -- ret=%d",
+ __func__, __LINE__, ret);
+ ret = SCST_TGT_RES_QUEUE_FULL;
+ } else {
+ PRINT_ERROR("%s[%d] fatal error -- ret=%d",
+ __func__, __LINE__, ret);
+ ret = SCST_TGT_RES_FATAL_ERROR;
+ }
+ goto out_unmap;
+ }
+
+ ret = SCST_TGT_RES_SUCCESS;
+
+out:
+ return ret;
+out_unmap:
+ srpt_unmap_sg_to_ib_sge(ch, ioctx);
+ goto out;
+}
+
+/**
+ * srpt_pending_cmd_timeout() - SCST command hw processing timeout callback.
+ *
+ * Called by the SCST core if no IB completion notification has been received
+ * within max_hw_pending_time seconds.
+ */
+static void srpt_pending_cmd_timeout(struct scst_cmd *scmnd)
+{
+ struct srpt_ioctx *ioctx;
+ enum srpt_command_state state;
+
+ ioctx = scst_cmd_get_tgt_priv(scmnd);
+ BUG_ON(!ioctx);
+
+ state = srpt_get_cmd_state(ioctx);
+ switch (state) {
+ case SRPT_STATE_NEW:
+ case SRPT_STATE_DATA_IN:
+ case SRPT_STATE_DONE:
+ /*
+ * srpt_pending_cmd_timeout() should never be invoked for
+ * commands in this state.
+ */
+ PRINT_ERROR("Processing SCST command %p (SRPT state %d) took"
+ " too long -- aborting", scmnd, state);
+ break;
+ case SRPT_STATE_NEED_DATA:
+ case SRPT_STATE_CMD_RSP_SENT:
+ case SRPT_STATE_MGMT_RSP_SENT:
+ default:
+ PRINT_ERROR("Command %p: IB completion for wr_id %u has not"
+ " been received in time (SRPT command state %d)",
+ scmnd, ioctx->index, state);
+ break;
+ }
+
+ srpt_abort_scst_cmd(ioctx, SCST_CONTEXT_SAME);
+}
+
+/**
+ * srpt_rdy_to_xfer() - Transfers data from initiator to target.
+ *
+ * Called by the SCST core to transfer data from the initiator to the target
+ * (SCST_DATA_WRITE). Must not block.
+ */
+static int srpt_rdy_to_xfer(struct scst_cmd *scmnd)
+{
+ struct srpt_rdma_ch *ch;
+ struct srpt_ioctx *ioctx;
+ enum srpt_command_state new_state;
+ enum rdma_ch_state ch_state;
+ int ret;
+
+ ioctx = scst_cmd_get_tgt_priv(scmnd);
+ BUG_ON(!ioctx);
+
+ new_state = srpt_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA);
+ WARN_ON(new_state == SRPT_STATE_DONE);
+
+ ch = ioctx->ch;
+ WARN_ON(ch != scst_sess_get_tgt_priv(scst_cmd_get_session(scmnd)));
+ BUG_ON(!ch);
+
+ ch_state = atomic_read(&ch->state);
+ if (ch_state == RDMA_CHANNEL_DISCONNECTING) {
+ TRACE_DBG("cmd with tag %lld: channel disconnecting",
+ scst_cmd_get_tag(scmnd));
+ ret = SCST_TGT_RES_FATAL_ERROR;
+ goto out;
+ } else if (ch_state == RDMA_CHANNEL_CONNECTING) {
+ ret = SCST_TGT_RES_QUEUE_FULL;
+ goto out;
+ }
+ ret = srpt_xfer_data(ch, ioctx, scmnd);
+
+out:
+ return ret;
+}
+
+/**
+ * srpt_must_wait_for_cred() - Whether or not the target must wait with
+ * sending a response towards the initiator in order to avoid that the
+ * initiator locks up. The Linux SRP initiator locks up when
+ * initiator.req_lim <= req_lim_min (req_lim_min equals 1 for SRP_CMD and
+ * equals 0 for SRP_TSK_MGMT) and either no new SRP_RSP will be received by the
+ * initiator or none of the received SRP_RSP responses increases
+ * initiator.req_lim. One possible strategy to avoid an initiator lockup is
+ * that the target does not send an SRP_RSP that makes initiator.req_lim <=
+ * req_lim_min. While the target does not know the value of initiator.req_lim,
+ * one can deduce from the credit mechanism specified in the SRP standard that
+ * when target.req_lim == req_lim_min, initiator.req_lim must also equal
+ * req_lim_min. Hence wait with sending a response when target.req_lim <=
+ * req_lim_min if that response would not increase initiator.req_lim. The last
+ * condition is equivalent to srpt_req_lim_delta(ch) <= 0.
+ *
+ * If this function returns false, the caller must either send a response to
+ * the initiator with the REQUEST LIMIT DELTA field set to delta or call
+ * srpt_undo_req_lim_delta(ch, delta); where delta is the value written to
+ * the address that is the third argument of this function.
+ *
+ * Note: The constant 'compensation' compensates for the fact that multiple
+ * threads are processing SRP commands simultaneously.
+ *
+ * See also: For more information about how to reproduce the initiator lockup,
+ * see also http://bugzilla.kernel.org/show_bug.cgi?id=14235.
+ */
+static bool srpt_must_wait_for_cred(struct srpt_rdma_ch *ch, int req_lim_min,
+ int *req_lim_delta)
+{
+ int delta;
+ bool res;
+ int compensation;
+ enum { default_vdisk_threads = 8 };
+
+ EXTRACHECKS_BUG_ON(!req_lim_delta);
+
+ compensation = min_t(int, default_vdisk_threads, num_online_cpus()) + 1;
+ res = true;
+ if (atomic_read(&ch->supports_cred_req)
+ || atomic_read(&ch->req_lim) > req_lim_min + compensation) {
+ res = false;
+ *req_lim_delta = srpt_req_lim_delta(ch);
+ } else {
+ bool again;
+ do {
+ again = false;
+ delta = atomic_read(&ch->req_lim_delta);
+ if (delta > 0) {
+ if (atomic_cmpxchg(&ch->req_lim_delta, delta, 0)
+ == delta) {
+ res = false;
+ *req_lim_delta = delta;
+ } else
+ again = true;
+ }
+ } while (again);
+ }
+ return res;
+}
+
+/**
+ * srpt_wait_for_cred() - Wait until sending a response won't lock up the
+ * initiator.
+ *
+ * The caller must either send a response to the initiator with the REQUEST
+ * LIMIT DELTA field set to delta + 1 or call srpt_undo_req_lim_delta(ch,
+ * delta); where delta is the return value of this function.
+ */
+static int srpt_wait_for_cred(struct srpt_rdma_ch *ch, int req_lim_min)
+{
+ int delta;
+
+#if 0
+ bool debug_print = atomic_read(&ch->req_lim) <= req_lim_min + 1;
+ if (debug_print)
+ PRINT_INFO("srpt_wait_for_cred(): min %d, req_lim %d,"
+ " req_lim_delta %d", req_lim_min,
+ atomic_read(&ch->req_lim),
+ atomic_read(&ch->req_lim_delta));
+#endif
+#if defined(CONFIG_SCST_DEBUG)
+ if (processing_delay_in_us <= MAX_UDELAY_MS * 1000)
+ udelay(processing_delay_in_us);
+#endif
+ delta = 0; /* superfluous -- to keep sparse happy */
+ while (unlikely(srpt_must_wait_for_cred(ch, req_lim_min, &delta))) {
+ atomic_inc(&ch->req_lim_waiter_count);
+ wait_for_completion(&ch->req_lim_compl);
+ }
+#if 0
+ if (debug_print)
+ PRINT_INFO("srpt_wait_for_cred() returns %d", delta);
+#endif
+ return delta;
+}
+
+/**
+ * srpt_xmit_response() - Transmits the response to a SCSI command.
+ *
+ * Callback function called by the SCST core. Must not block. Must ensure that
+ * scst_tgt_cmd_done() will get invoked when returning SCST_TGT_RES_SUCCESS.
+ */
+static int srpt_xmit_response(struct scst_cmd *scmnd)
+{
+ struct srpt_rdma_ch *ch;
+ struct srpt_ioctx *ioctx;
+ enum srpt_command_state state;
+ s32 req_lim_delta;
+ int ret;
+ scst_data_direction dir;
+ int resp_len;
+
+ ret = SCST_TGT_RES_SUCCESS;
+
+ ioctx = scst_cmd_get_tgt_priv(scmnd);
+ BUG_ON(!ioctx);
+
+ ch = scst_sess_get_tgt_priv(scst_cmd_get_session(scmnd));
+ BUG_ON(!ch);
+
+ state = srpt_test_and_set_cmd_state(ioctx, SRPT_STATE_NEW,
+ SRPT_STATE_CMD_RSP_SENT);
+ if (state != SRPT_STATE_NEW) {
+ state = srpt_test_and_set_cmd_state(ioctx, SRPT_STATE_DATA_IN,
+ SRPT_STATE_CMD_RSP_SENT);
+ if (state != SRPT_STATE_DATA_IN)
+ PRINT_ERROR("Unexpected command state %d",
+ srpt_get_cmd_state(ioctx));
+ }
+
+ if (unlikely(scst_cmd_aborted(scmnd))) {
+ srpt_abort_scst_cmd(ioctx, SCST_CONTEXT_SAME);
+ goto out;
+ }
+
+ EXTRACHECKS_BUG_ON(scst_cmd_atomic(scmnd));
+
+ dir = scst_cmd_get_data_direction(scmnd);
+
+ /* For read commands, transfer the data to the initiator. */
+ if (dir == SCST_DATA_READ
+ && scst_cmd_get_adjusted_resp_data_len(scmnd)) {
+ ret = srpt_xfer_data(ch, ioctx, scmnd);
+ if (ret != SCST_TGT_RES_SUCCESS) {
+ PRINT_ERROR("%s: tag= %llu xfer_data failed",
+ __func__, scst_cmd_get_tag(scmnd));
+ goto out;
+ }
+ }
+
+ req_lim_delta = srpt_wait_for_cred(ch, 1);
+
+ resp_len = srpt_build_cmd_rsp(ch, ioctx, req_lim_delta,
+ scst_cmd_get_tag(scmnd),
+ scst_cmd_get_status(scmnd),
+ scst_cmd_get_sense_buffer(scmnd),
+ scst_cmd_get_sense_buffer_len(scmnd));
+
+ if (srpt_post_send(ch, ioctx, resp_len)) {
+ srpt_unmap_sg_to_ib_sge(ch, ioctx);
+ srpt_set_cmd_state(ioctx, state);
+ scst_set_delivery_status(scmnd, SCST_CMD_DELIVERY_FAILED);
+ PRINT_ERROR("%s[%d]: ch->state %d cmd state %d tag %llu",
+ __func__, __LINE__, atomic_read(&ch->state),
+ state, scst_cmd_get_tag(scmnd));
+ srpt_undo_req_lim_delta(ch, req_lim_delta - 1);
+ ret = SCST_TGT_RES_QUEUE_FULL;
+ }
+
+out:
+ return ret;
+}
+
+/**
+ * srpt_tsk_mgmt_done() - SCST callback function that sends back the response
+ * for a task management request.
+ *
+ * Must not block.
+ */
+static void srpt_tsk_mgmt_done(struct scst_mgmt_cmd *mcmnd)
+{
+ struct srpt_rdma_ch *ch;
+ struct srpt_mgmt_ioctx *mgmt_ioctx;
+ struct srpt_ioctx *ioctx;
+ enum srpt_command_state new_state;
+ s32 req_lim_delta;
+ int rsp_len;
+
+ mgmt_ioctx = scst_mgmt_cmd_get_tgt_priv(mcmnd);
+ BUG_ON(!mgmt_ioctx);
+
+ ch = mgmt_ioctx->ch;
+ BUG_ON(!ch);
+
+ ioctx = mgmt_ioctx->ioctx;
+ BUG_ON(!ioctx);
+
+ TRACE_DBG("%s: tsk_mgmt_done for tag= %lld status=%d",
+ __func__, mgmt_ioctx->tag, scst_mgmt_cmd_get_status(mcmnd));
+
+ WARN_ON(in_irq());
+
+ new_state = srpt_set_cmd_state(ioctx, SRPT_STATE_MGMT_RSP_SENT);
+ WARN_ON(new_state == SRPT_STATE_DONE);
+
+ req_lim_delta = srpt_wait_for_cred(ch, 0);
+
+ rsp_len = srpt_build_tskmgmt_rsp(ch, ioctx, req_lim_delta,
+ scst_to_srp_tsk_mgmt_status(
+ scst_mgmt_cmd_get_status(mcmnd)),
+ mgmt_ioctx->tag);
+ /*
+ * Note: the srpt_post_send() call below sends the task management
+ * response asynchronously. It is possible that the SCST core has
+ * already freed the struct scst_mgmt_cmd structure before the
+ * response is sent. This is fine.
+ */
+ if (srpt_post_send(ch, ioctx, rsp_len)) {
+ PRINT_ERROR("%s", "Sending SRP_RSP response failed.");
+ srpt_undo_req_lim_delta(ch, req_lim_delta - 1);
+ }
+
+ scst_mgmt_cmd_set_tgt_priv(mcmnd, NULL);
+
+ kfree(mgmt_ioctx);
+}
+
+/**
+ * srpt_get_initiator_port_transport_id() - SCST TransportID callback function.
+ *
+ * See also SPC-3, section 7.5.4.5, TransportID for initiator ports using SRP.
+ */
+static int srpt_get_initiator_port_transport_id(struct scst_session *scst_sess,
+ uint8_t **transport_id)
+{
+ struct srpt_rdma_ch *ch;
+ struct spc_rdma_transport_id {
+ uint8_t protocol_identifier;
+ uint8_t reserved[7];
+ uint8_t i_port_id[16];
+ };
+ struct spc_rdma_transport_id *tr_id;
+ int res;
+
+ if (!scst_sess) {
+ res = SCSI_TRANSPORTID_PROTOCOLID_SRP;
+ goto out;
+ }
+
+ ch = scst_sess_get_tgt_priv(scst_sess);
+ BUG_ON(!ch);
+
+ BUILD_BUG_ON(sizeof(*tr_id) != 24);
+
+ tr_id = kzalloc(sizeof(struct spc_rdma_transport_id), GFP_KERNEL);
+ if (!tr_id) {
+ PRINT_ERROR("%s", "Allocation of TransportID failed");
+ res = -ENOMEM;
+ goto out;
+ }
+
+ res = 0;
+ tr_id->protocol_identifier = SCSI_TRANSPORTID_PROTOCOLID_SRP;
+ memcpy(tr_id->i_port_id, ch->i_port_id, sizeof(ch->i_port_id));
+
+ *transport_id = (uint8_t *)tr_id;
+
+out:
+ return res;
+}
+
+/**
+ * srpt_on_free_cmd() - Free command-private data.
+ *
+ * Called by the SCST core. May be called in IRQ context.
+ */
+static void srpt_on_free_cmd(struct scst_cmd *scmnd)
+{
+ struct srpt_rdma_ch *ch;
+ struct srpt_ioctx *ioctx;
+
+ ioctx = scst_cmd_get_tgt_priv(scmnd);
+ BUG_ON(!ioctx);
+
+ WARN_ON(srpt_get_cmd_state(ioctx) != SRPT_STATE_DONE);
+
+ ch = ioctx->ch;
+ BUG_ON(!ch);
+
+ srpt_reset_ioctx(ch, ioctx, 1);
+}
+
+static void srpt_refresh_port_work(struct work_struct *work)
+{
+ struct srpt_port *sport = container_of(work, struct srpt_port, work);
+
+ srpt_refresh_port(sport);
+}
+
+/**
+ * srpt_detect() - Returns the number of target adapters.
+ *
+ * Callback function called by the SCST core.
+ */
+static int srpt_detect(struct scst_tgt_template *tp)
+{
+ int device_count;
+
+ device_count = atomic_read(&srpt_device_count);
+
+ return device_count;
+}
+
+/**
+ * srpt_release() - Free the resources associated with an SCST target.
+ *
+ * Callback function called by the SCST core from scst_unregister_target().
+ */
+static int srpt_release(struct scst_tgt *scst_tgt)
+{
+ struct srpt_device *sdev = scst_tgt_get_tgt_priv(scst_tgt);
+ struct srpt_rdma_ch *ch;
+
+ EXTRACHECKS_WARN_ON_ONCE(irqs_disabled());
+
+ BUG_ON(!scst_tgt);
+ if (WARN_ON(!sdev))
+ return -ENODEV;
+
+ spin_lock_irq(&sdev->spinlock);
+ while (!list_empty(&sdev->rch_list)) {
+ ch = list_first_entry(&sdev->rch_list, typeof(*ch), list);
+ srpt_unregister_channel(ch);
+ }
+ spin_unlock_irq(&sdev->spinlock);
+
+ scst_tgt_set_tgt_priv(scst_tgt, NULL);
+
+ return 0;
+}
+
+/**
+ * srpt_get_scsi_transport_version() - Returns the SCSI transport version.
+ * This function is called from scst_pres.c, the code that implements
+ * persistent reservation support.
+ */
+static uint16_t srpt_get_scsi_transport_version(struct scst_tgt *scst_tgt)
+{
+ return 0x0940; /* SRP */
+}
+
+/* SCST target template for the SRP target implementation. */
+static struct scst_tgt_template srpt_template = {
+ .name = DRV_NAME,
+ .sg_tablesize = SRPT_DEF_SG_TABLESIZE,
+ .max_hw_pending_time = 60/*seconds*/,
+ .enable_target = srpt_enable_target,
+ .is_target_enabled = srpt_is_target_enabled,
+#if defined(CONFIG_SCST_DEBUG) || defined(CONFIG_SCST_TRACING)
+ .default_trace_flags = DEFAULT_SRPT_TRACE_FLAGS,
+ .trace_flags = &trace_flag,
+#endif
+ .detect = srpt_detect,
+ .release = srpt_release,
+ .xmit_response = srpt_xmit_response,
+ .rdy_to_xfer = srpt_rdy_to_xfer,
+ .on_hw_pending_cmd_timeout = srpt_pending_cmd_timeout,
+ .on_free_cmd = srpt_on_free_cmd,
+ .task_mgmt_fn_done = srpt_tsk_mgmt_done,
+ .get_initiator_port_transport_id = srpt_get_initiator_port_transport_id,
+ .get_scsi_transport_version = srpt_get_scsi_transport_version,
+};
+
+/**
+ * srpt_dev_release() - Device release callback function.
+ *
+ * The callback function srpt_dev_release() is called whenever a
+ * device is removed from the /sys/class/infiniband_srpt device class.
+ * Although this function has been left empty, a release function has been
+ * defined such that upon module removal no complaint is logged about a
+ * missing release function.
+ */
+static void srpt_dev_release(struct device *dev)
+{
+}
+
+static ssize_t show_login_info(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct srpt_device *sdev =
+ container_of(dev, struct srpt_device, dev);
+ struct srpt_port *sport;
+ int i;
+ int len = 0;
+
+ for (i = 0; i < sdev->device->phys_port_cnt; i++) {
+ sport = &sdev->port[i];
+
+ len += sprintf(buf + len,
+ "tid_ext=%016llx,ioc_guid=%016llx,pkey=ffff,"
+ "dgid=%04x%04x%04x%04x%04x%04x%04x%04x,"
+ "service_id=%016llx\n",
+ srpt_service_guid,
+ srpt_service_guid,
+ be16_to_cpu(((__be16 *) sport->gid.raw)[0]),
+ be16_to_cpu(((__be16 *) sport->gid.raw)[1]),
+ be16_to_cpu(((__be16 *) sport->gid.raw)[2]),
+ be16_to_cpu(((__be16 *) sport->gid.raw)[3]),
+ be16_to_cpu(((__be16 *) sport->gid.raw)[4]),
+ be16_to_cpu(((__be16 *) sport->gid.raw)[5]),
+ be16_to_cpu(((__be16 *) sport->gid.raw)[6]),
+ be16_to_cpu(((__be16 *) sport->gid.raw)[7]),
+ srpt_service_guid);
+ }
+
+ return len;
+}
+
+static struct class_attribute srpt_class_attrs[] = {
+ __ATTR_NULL,
+};
+
+static struct device_attribute srpt_dev_attrs[] = {
+ __ATTR(login_info, S_IRUGO, show_login_info, NULL),
+ __ATTR_NULL,
+};
+
+static struct class srpt_class = {
+ .name = "infiniband_srpt",
+ .dev_release = srpt_dev_release,
+ .class_attrs = srpt_class_attrs,
+ .dev_attrs = srpt_dev_attrs,
+};
+
+/**
+ * srpt_add_one() - Infiniband device addition callback function.
+ */
+static void srpt_add_one(struct ib_device *device)
+{
+ struct srpt_device *sdev;
+ struct srpt_port *sport;
+ struct ib_srq_init_attr srq_attr;
+ int i;
+
+ TRACE_DBG("device = %p, device->dma_ops = %p", device, device->dma_ops);
+
+ sdev = kzalloc(sizeof *sdev, GFP_KERNEL);
+ if (!sdev)
+ return;
+
+ sdev->scst_tgt = scst_register_target(&srpt_template, NULL);
+ if (!sdev->scst_tgt) {
+ PRINT_ERROR("SCST registration failed for %s.",
+ sdev->device->name);
+ goto free_dev;
+ }
+
+ scst_tgt_set_tgt_priv(sdev->scst_tgt, sdev);
+
+ sdev->device = device;
+
+ sdev->dev.class = &srpt_class;
+ sdev->dev.parent = device->dma_device;
+ dev_set_name(&sdev->dev, "srpt-%s", device->name);
+
+ if (device_register(&sdev->dev))
+ goto unregister_tgt;
+
+ if (ib_query_device(device, &sdev->dev_attr))
+ goto err_dev;
+
+ sdev->pd = ib_alloc_pd(device);
+ if (IS_ERR(sdev->pd))
+ goto err_dev;
+
+ sdev->mr = ib_get_dma_mr(sdev->pd, IB_ACCESS_LOCAL_WRITE);
+ if (IS_ERR(sdev->mr))
+ goto err_pd;
+
+ sdev->srq_size = min(srpt_srq_size, sdev->dev_attr.max_srq_wr);
+
+ srq_attr.event_handler = srpt_srq_event;
+ srq_attr.srq_context = (void *)sdev;
+ srq_attr.attr.max_wr = sdev->srq_size;
+ srq_attr.attr.max_sge = 1;
+ srq_attr.attr.srq_limit = 0;
+
+ sdev->srq = ib_create_srq(sdev->pd, &srq_attr);
+ if (IS_ERR(sdev->srq))
+ goto err_mr;
+
+ TRACE_DBG("%s: create SRQ #wr= %d max_allow=%d dev= %s",
+ __func__, sdev->srq_size,
+ sdev->dev_attr.max_srq_wr, device->name);
+
+ if (!srpt_service_guid)
+ srpt_service_guid = be64_to_cpu(device->node_guid);
+
+ sdev->cm_id = ib_create_cm_id(device, srpt_cm_handler, sdev);
+ if (IS_ERR(sdev->cm_id))
+ goto err_srq;
+
+ /* print out target login information */
+ TRACE_DBG("Target login info: id_ext=%016llx,"
+ "ioc_guid=%016llx,pkey=ffff,service_id=%016llx",
+ srpt_service_guid, srpt_service_guid, srpt_service_guid);
+
+ /*
+ * We do not have a consistent service_id (ie. also id_ext of target_id)
+ * to identify this target. We currently use the guid of the first HCA
+ * in the system as service_id; therefore, the target_id will change
+ * if this HCA is gone bad and replaced by different HCA
+ */
+ if (ib_cm_listen(sdev->cm_id, cpu_to_be64(srpt_service_guid), 0, NULL))
+ goto err_cm;
+
+ INIT_IB_EVENT_HANDLER(&sdev->event_handler, sdev->device,
+ srpt_event_handler);
+ if (ib_register_event_handler(&sdev->event_handler))
+ goto err_cm;
+
+ sdev->ioctx_ring = kmalloc(sdev->srq_size * sizeof sdev->ioctx_ring[0],
+ GFP_KERNEL);
+ if (!sdev->ioctx_ring)
+ goto err_event;
+
+ if (srpt_alloc_ioctx_ring(sdev, sdev->ioctx_ring, sdev->srq_size, 0))
+ goto err_alloc_ring;
+
+ INIT_LIST_HEAD(&sdev->rch_list);
+ spin_lock_init(&sdev->spinlock);
+
+ for (i = 0; i < sdev->srq_size; ++i)
+ srpt_post_recv(sdev, sdev->ioctx_ring[i]);
+
+ ib_set_client_data(device, &srpt_client, sdev);
+
+ WARN_ON(sdev->device->phys_port_cnt
+ > sizeof(sdev->port)/sizeof(sdev->port[0]));
+
+ for (i = 1; i <= sdev->device->phys_port_cnt; i++) {
+ sport = &sdev->port[i - 1];
+ sport->sdev = sdev;
+ sport->port = i;
+ INIT_WORK(&sport->work, srpt_refresh_port_work);
+ if (srpt_refresh_port(sport)) {
+ PRINT_ERROR("MAD registration failed for %s-%d.",
+ sdev->device->name, i);
+ goto err_ring;
+ }
+ }
+
+ atomic_inc(&srpt_device_count);
+
+ return;
+
+err_ring:
+ ib_set_client_data(device, &srpt_client, NULL);
+ srpt_free_ioctx_ring(sdev, sdev->ioctx_ring, sdev->srq_size);
+err_alloc_ring:
+ kfree(sdev->ioctx_ring);
+err_event:
+ ib_unregister_event_handler(&sdev->event_handler);
+err_cm:
+ ib_destroy_cm_id(sdev->cm_id);
+err_srq:
+ ib_destroy_srq(sdev->srq);
+err_mr:
+ ib_dereg_mr(sdev->mr);
+err_pd:
+ ib_dealloc_pd(sdev->pd);
+err_dev:
+ device_unregister(&sdev->dev);
+unregister_tgt:
+ scst_unregister_target(sdev->scst_tgt);
+free_dev:
+ kfree(sdev);
+}
+
+/**
+ * srpt_remove_one() - InfiniBand device removal callback function.
+ */
+static void srpt_remove_one(struct ib_device *device)
+{
+ int i;
+ struct srpt_device *sdev;
+
+ sdev = ib_get_client_data(device, &srpt_client);
+ if (WARN_ON(!sdev))
+ return;
+
+ srpt_unregister_mad_agent(sdev);
+
+ ib_unregister_event_handler(&sdev->event_handler);
+
+ /* Cancel any work queued by the just unregistered IB event handler. */
+ for (i = 0; i < sdev->device->phys_port_cnt; i++)
+ cancel_work_sync(&sdev->port[i].work);
+
+ ib_destroy_cm_id(sdev->cm_id);
+ ib_destroy_srq(sdev->srq);
+ ib_dereg_mr(sdev->mr);
+ ib_dealloc_pd(sdev->pd);
+
+ device_unregister(&sdev->dev);
+
+ /*
+ * Unregistering an SCST target must happen after destroying sdev->cm_id
+ * such that no new SRP_LOGIN_REQ information units can arrive while
+ * destroying the SCST target.
+ */
+ scst_unregister_target(sdev->scst_tgt);
+ sdev->scst_tgt = NULL;
+
+ srpt_free_ioctx_ring(sdev, sdev->ioctx_ring, sdev->srq_size);
+ kfree(sdev->ioctx_ring);
+ sdev->ioctx_ring = NULL;
+ kfree(sdev);
+}
+
+/**
+ * srpt_init_module() - Kernel module initialization.
+ *
+ * Note: Since ib_register_client() registers callback functions, and since at
+ * least one of these callback functions (srpt_add_one()) calls SCST functions,
+ * the SCST target template must be registered before ib_register_client() is
+ * called.
+ */
+static int __init srpt_init_module(void)
+{
+ int ret;
+
+ ret = -EINVAL;
+ if (srp_max_message_size < MIN_MAX_MESSAGE_SIZE) {
+ PRINT_ERROR("invalid value %d for kernel module parameter"
+ " srp_max_message_size -- must be at least %d.",
+ srp_max_message_size,
+ MIN_MAX_MESSAGE_SIZE);
+ goto out;
+ }
+
+ if (srpt_srq_size < MIN_SRPT_SRQ_SIZE
+ || srpt_srq_size > MAX_SRPT_SRQ_SIZE) {
+ PRINT_ERROR("invalid value %d for kernel module parameter"
+ " srpt_srq_size -- must be in the range [%d..%d].",
+ srpt_srq_size, MIN_SRPT_SRQ_SIZE,
+ MAX_SRPT_SRQ_SIZE);
+ goto out;
+ }
+
+ if (srpt_sq_size < MIN_SRPT_SQ_SIZE) {
+ PRINT_ERROR("invalid value %d for kernel module parameter"
+ " srpt_sq_size -- must be at least %d.",
+ srpt_srq_size, MIN_SRPT_SQ_SIZE);
+ goto out;
+ }
+
+ ret = class_register(&srpt_class);
+ if (ret) {
+ PRINT_ERROR("%s", "couldn't register class ib_srpt");
+ goto out;
+ }
+
+ switch (thread) {
+ case MODE_ALL_IN_SIRQ:
+ /*
+ * Process both IB completions and SCST commands in SIRQ
+ * context. May lead to soft lockups and other scary behavior
+ * under sufficient load.
+ */
+ srpt_template.rdy_to_xfer_atomic = true;
+ break;
+ case MODE_IB_COMPLETION_IN_THREAD:
+ /*
+ * Process IB completions in the kernel thread associated with
+ * the RDMA channel, and process SCST commands in the kernel
+ * threads created by the SCST core.
+ */
+ srpt_template.rdy_to_xfer_atomic = false;
+ break;
+ case MODE_IB_COMPLETION_IN_SIRQ:
+ default:
+ /*
+ * Process IB completions in SIRQ context and SCST commands in
+ * the kernel threads created by the SCST core.
+ */
+ srpt_template.rdy_to_xfer_atomic = false;
+ break;
+ }
+
+ ret = scst_register_target_template(&srpt_template);
+ if (ret < 0) {
+ PRINT_ERROR("%s", "couldn't register with scst");
+ ret = -ENODEV;
+ goto out_unregister_class;
+ }
+
+ ret = ib_register_client(&srpt_client);
+ if (ret) {
+ PRINT_ERROR("%s", "couldn't register IB client");
+ goto out_unregister_procfs;
+ }
+
+ return 0;
+
+out_unregister_procfs:
+ scst_unregister_target_template(&srpt_template);
+out_unregister_class:
+ class_unregister(&srpt_class);
+out:
+ return ret;
+}
+
+static void __exit srpt_cleanup_module(void)
+{
+
+ ib_unregister_client(&srpt_client);
+ scst_unregister_target_template(&srpt_template);
+ class_unregister(&srpt_class);
+}
+
+module_init(srpt_init_module);
+module_exit(srpt_cleanup_module);
+
+/*
+ * Local variables:
+ * c-basic-offset: 8
+ * indent-tabs-mode: t
+ * End:
+ */
diff -uprN orig/linux-2.6.35/drivers/scst/srpt/ib_srpt.h linux-2.6.35/drivers/scst/srpt/ib_srpt.h
--- orig/linux-2.6.35/drivers/scst/srpt/ib_srpt.h
+++ linux-2.6.35/drivers/scst/srpt/ib_srpt.h
@@ -0,0 +1,370 @@
+/*
+ * Copyright (c) 2006 - 2009 Mellanox Technology Inc. All rights reserved.
+ * Copyright (C) 2009 - 2010 Bart Van Assche <bart.vanassche@...il.com>
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+#ifndef IB_SRPT_H
+#define IB_SRPT_H
+
+#include <linux/version.h>
+#include <linux/types.h>
+#include <linux/list.h>
+
+#include <rdma/ib_verbs.h>
+#include <rdma/ib_sa.h>
+#include <rdma/ib_cm.h>
+
+#include <scsi/srp.h>
+
+#include <scst/scst.h>
+
+#include "ib_dm_mad.h"
+
+/*
+ * The prefix the ServiceName field must start with in the device management
+ * ServiceEntries attribute pair. See also the SRP r16a document.
+ */
+#define SRP_SERVICE_NAME_PREFIX "SRP.T10:"
+
+enum {
+ /*
+ * SRP IOControllerProfile attributes for SRP target ports that have
+ * not been defined in <scsi/srp.h>. Source: section B.7, table B.7
+ * in the SRP r16a document.
+ */
+ SRP_PROTOCOL = 0x0108,
+ SRP_PROTOCOL_VERSION = 0x0001,
+ SRP_IO_SUBCLASS = 0x609e,
+ SRP_SEND_TO_IOC = 0x01,
+ SRP_SEND_FROM_IOC = 0x02,
+ SRP_RDMA_READ_FROM_IOC = 0x08,
+ SRP_RDMA_WRITE_FROM_IOC = 0x20,
+
+ /*
+ * srp_login_cmd::req_flags bitmasks. See also table 9 in the SRP r16a
+ * document.
+ */
+ SRP_MTCH_ACTION = 0x03, /* MULTI-CHANNEL ACTION */
+ SRP_LOSOLNT = 0x10, /* logout solicited notification */
+ SRP_CRSOLNT = 0x20, /* credit request solicited notification */
+ SRP_AESOLNT = 0x40, /* asynchronous event solicited notification */
+
+ /*
+ * srp_cmd::sol_nt / srp_tsk_mgmt::sol_not bitmasks. See also tables
+ * 18 and 20 in the T10 r16a document.
+ */
+ SRP_SCSOLNT = 0x02, /* SCSOLNT = successful solicited notification */
+ SRP_UCSOLNT = 0x04, /* UCSOLNT = unsuccessful solicited notification */
+
+ /*
+ * srp_rsp::sol_not / srp_t_logout::sol_not bitmasks. See also tables
+ * 16 and 22 in the T10 r16a document.
+ */
+ SRP_SOLNT = 0x01, /* SOLNT = solicited notification */
+
+ /* See also table 24 in the T10 r16a document. */
+ SRP_TSK_MGMT_SUCCESS = 0x00,
+ SRP_TSK_MGMT_FUNC_NOT_SUPP = 0x04,
+ SRP_TSK_MGMT_FAILED = 0x05,
+
+ /* See also table 21 in the T10 r16a document. */
+ SRP_CMD_SIMPLE_Q = 0x0,
+ SRP_CMD_HEAD_OF_Q = 0x1,
+ SRP_CMD_ORDERED_Q = 0x2,
+ SRP_CMD_ACA = 0x4,
+
+ SRP_LOGIN_RSP_MULTICHAN_NO_CHAN = 0x0,
+ SRP_LOGIN_RSP_MULTICHAN_TERMINATED = 0x1,
+ SRP_LOGIN_RSP_MULTICHAN_MAINTAINED = 0x2,
+
+ SRPT_DEF_SG_TABLESIZE = 128,
+ SRPT_DEF_SG_PER_WQE = 16,
+
+ MIN_SRPT_SQ_SIZE = 16,
+ DEF_SRPT_SQ_SIZE = 4096,
+ SRPT_RQ_SIZE = 128,
+ MIN_SRPT_SRQ_SIZE = 4,
+ DEFAULT_SRPT_SRQ_SIZE = 4095,
+ MAX_SRPT_SRQ_SIZE = 65535,
+
+ MIN_MAX_MESSAGE_SIZE = 996,
+ DEFAULT_MAX_MESSAGE_SIZE
+ = sizeof(struct srp_cmd)/*48*/
+ + sizeof(struct srp_indirect_buf)/*20*/
+ + 128 * sizeof(struct srp_direct_buf)/*16*/,
+
+ DEFAULT_MAX_RDMA_SIZE = 65536,
+
+ /*
+ * Number of I/O contexts to be allocated for sending back requests
+ * from the target to the initiator. Must be a power of two.
+ */
+ TTI_IOCTX_COUNT = 2,
+ TTI_IOCTX_MASK = TTI_IOCTX_COUNT - 1,
+};
+
+/**
+ * @SRPT_OP_TTI: wr_id flag for marking requests sent by the target to the
+ * initiator.
+ * @SRPT_OP_RECV: wr_id flag for marking receive operations.
+ */
+enum {
+ SRPT_OP_TTI = (1 << 30),
+ SRPT_OP_RECV = (1 << 31),
+
+ SRPT_OP_FLAGS = SRPT_OP_TTI | SRPT_OP_RECV,
+};
+
+/*
+ * SRP_CRED_REQ information unit, as defined in section 6.10 of the T10 SRP
+ * r16a document.
+ */
+struct srp_cred_req {
+ u8 opcode;
+ u8 sol_not;
+ u8 reserved[2];
+ __be32 req_lim_delta;
+ __be64 tag;
+};
+
+struct rdma_iu {
+ u64 raddr;
+ u32 rkey;
+ struct ib_sge *sge;
+ u32 sge_cnt;
+ int mem_id;
+};
+
+/**
+ * enum srpt_command_state - SCSI command states managed by SRPT.
+ * @SRPT_STATE_NEW: New command arrived and is being processed.
+ * @SRPT_STATE_NEED_DATA: Processing a write or bidir command and waiting
+ * for data arrival.
+ * @SRPT_STATE_DATA_IN: Data for the write or bidir command arrived and is
+ * being processed.
+ * @SRPT_STATE_CMD_RSP_SENT: SRP_RSP for SRP_CMD has been sent.
+ * @SRPT_STATE_MGMT_RSP_SENT: SRP_RSP for SRP_TSK_MGMT has been sent.
+ * @SRPT_STATE_DONE: Command processing finished successfully, command
+ * processing has been aborted or command processing
+ * failed.
+ */
+enum srpt_command_state {
+ SRPT_STATE_NEW = 0,
+ SRPT_STATE_NEED_DATA = 1,
+ SRPT_STATE_DATA_IN = 2,
+ SRPT_STATE_CMD_RSP_SENT = 3,
+ SRPT_STATE_MGMT_RSP_SENT = 4,
+ SRPT_STATE_DONE = 5,
+};
+
+/**
+ * struct srpt_ioctx - SRPT-private data associated with a struct scst_cmd.
+ * @index: Index of the I/O context in ioctx_ring.
+ * @buf: Pointer to the message transferred via this I/O context.
+ * @dma: DMA address of buf.
+ * @wait_list: Node for insertion in srpt_rdma_ch::cmd_wait_list.
+ * @state: I/O context state. See also enum srpt_command_state.
+ */
+struct srpt_ioctx {
+ int index;
+ void *buf;
+ dma_addr_t dma;
+ struct rdma_iu *rdma_ius;
+ struct srp_direct_buf *rbufs;
+ struct srp_direct_buf single_rbuf;
+ struct list_head wait_list;
+ struct scatterlist *sg;
+ int sg_cnt;
+ int mapped_sg_count;
+ u16 n_rdma_ius;
+ u8 n_rdma;
+ u8 n_rbuf;
+
+ u64 wr_id;
+ enum ib_wc_status status;
+ enum ib_wc_opcode opcode;
+ struct srpt_rdma_ch *ch;
+ struct scst_cmd *scmnd;
+ scst_data_direction dir;
+ atomic_t state;
+};
+
+/**
+ * struct srpt_mgmt_ioctx - SCST management command context information.
+ * @ioctx: SRPT I/O context associated with the management command.
+ * @ch: RDMA channel over which the management command has been received.
+ * @tag: SCSI tag of the management command.
+ */
+struct srpt_mgmt_ioctx {
+ struct srpt_ioctx *ioctx;
+ struct srpt_rdma_ch *ch;
+ u64 tag;
+};
+
+/**
+ * enum rdma_ch_state - SRP channel state.
+ */
+enum rdma_ch_state {
+ RDMA_CHANNEL_CONNECTING,
+ RDMA_CHANNEL_LIVE,
+ RDMA_CHANNEL_DISCONNECTING
+};
+
+/**
+ * struct srpt_rdma_ch - RDMA channel.
+ * @wait_queue: Allows the kernel thread to wait for more work.
+ * @thread: Kernel thread that processes the IB queues associated with
+ * the channel.
+ * @cm_id: IB CM ID associated with the channel.
+ * @rq_size: IB receive queue size.
+ * @processing_compl: whether or not an IB completion is being processed.
+ * @qp: IB queue pair used for communicating over this channel.
+ * @sq_wr_avail: number of work requests available in the send queue.
+ * @cq: IB completion queue for this channel.
+ * @sport: pointer to the information of the HCA port used by this
+ * channel.
+ * @i_port_id: 128-bit initiator port identifier copied from SRP_LOGIN_REQ.
+ * @t_port_id: 128-bit target port identifier copied from SRP_LOGIN_REQ.
+ * @max_ti_iu_len: maximum target-to-initiator information unit length.
+ * @supports_cred_req: whether or not the initiator supports SRP_CRED_REQ.
+ * @req_lim: request limit: maximum number of requests that may be sent
+ * by the initiator without having received a response or
+ * SRP_CRED_REQ.
+ * @req_lim_delta: req_lim_delta to be sent in the next SRP_RSP.
+ * @req_lim_waiter_count: number of threads waiting on req_lim_wait.
+ * @req_lim_compl: completion variable that is signalled every time req_lim
+ * has been incremented.
+ * @state: channel state. See also enum rdma_ch_state.
+ * @list: node for insertion in the srpt_device::rch_list list.
+ * @cmd_wait_list: list of SCST commands that arrived before the RTU event. This
+ * list contains struct srpt_ioctx elements and is protected
+ * against concurrent modification by the cm_id spinlock.
+ * @tti_head: Index of first element of tti_ioctx that is not in use.
+ * @tti_tail: Index of first element of tti_ioctx that is in use.
+ * @tti_ioctx: Circular buffer with I/O contexts for sending requests from
+ * target to initiator.
+ * @scst_sess: SCST session information associated with this SRP channel.
+ * @sess_name: SCST session name.
+ */
+struct srpt_rdma_ch {
+ wait_queue_head_t wait_queue;
+ struct task_struct *thread;
+ struct ib_cm_id *cm_id;
+ struct ib_qp *qp;
+ int rq_size;
+ atomic_t processing_compl;
+ struct ib_cq *cq;
+ atomic_t sq_wr_avail;
+ struct srpt_port *sport;
+ u8 i_port_id[16];
+ u8 t_port_id[16];
+ int max_ti_iu_len;
+ atomic_t supports_cred_req;
+ atomic_t req_lim;
+ atomic_t req_lim_delta;
+ atomic_t req_lim_waiter_count;
+ struct completion req_lim_compl;
+ atomic_t state;
+ struct list_head list;
+ struct list_head cmd_wait_list;
+ int tti_head;
+ int tti_tail;
+ struct srpt_ioctx *tti_ioctx[TTI_IOCTX_COUNT];
+
+ struct scst_session *scst_sess;
+ u8 sess_name[36];
+};
+
+/**
+ * struct srpt_port - Information associated by SRPT with a single IB port.
+ * @sdev: backpointer to the HCA information.
+ * @mad_agent: per-port management datagram processing information.
+ * @port: one-based port number.
+ * @sm_lid: cached value of the port's sm_lid.
+ * @lid: cached value of the port's lid.
+ * @gid: cached value of the port's gid.
+ * @work: work structure for refreshing the aforementioned cached values.
+ */
+struct srpt_port {
+ struct srpt_device *sdev;
+ struct ib_mad_agent *mad_agent;
+ u8 port;
+ u16 sm_lid;
+ u16 lid;
+ union ib_gid gid;
+ struct work_struct work;
+};
+
+/**
+ * struct srpt_device - Information associated by SRPT with a single HCA.
+ * @device: backpointer to the struct ib_device managed by the IB core.
+ * @pd: IB protection domain.
+ * @mr: L_Key (local key) with write access to all local memory.
+ * @srq: Per-HCA SRQ (shared receive queue).
+ * @cm_id: connection identifier.
+ * @dev_attr: attributes of the InfiniBand device as obtained during the
+ * ib_client::add() callback.
+ * @ioctx_ring: Per-HCA I/O context ring.
+ * @rch_list: per-device channel list -- see also srpt_rdma_ch::list.
+ * @spinlock: protects rch_list.
+ * @srpt_port: information about the ports owned by this HCA.
+ * @event_handler: per-HCA asynchronous IB event handler.
+ * @dev: per-port srpt-<portname> device instance.
+ * @scst_tgt: SCST target information associated with this HCA.
+ * @enabled: Whether or not this SCST target is enabled.
+ */
+struct srpt_device {
+ struct ib_device *device;
+ struct ib_pd *pd;
+ struct ib_mr *mr;
+ struct ib_srq *srq;
+ struct ib_cm_id *cm_id;
+ struct ib_device_attr dev_attr;
+ int srq_size;
+ struct srpt_ioctx **ioctx_ring;
+ struct list_head rch_list;
+ spinlock_t spinlock;
+ struct srpt_port port[2];
+ struct ib_event_handler event_handler;
+ struct device dev;
+ struct scst_tgt *scst_tgt;
+ bool enabled;
+};
+
+#endif /* IB_SRPT_H */
+
+/*
+ * Local variables:
+ * c-basic-offset: 8
+ * indent-tabs-mode: t
+ * End:
+ */
---
README.srpt | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 112 insertions(+)
diff -uprN orig/linux-2.6.35/Documentation/scst/README.srpt linux-2.6.35/Documentation/scst/README.srpt
--- orig/linux-2.6.35/Documentation/scst/README.srpt
+++ linux-2.6.35/Documentation/scst/README.srpt
@@ -0,0 +1,112 @@
+SCSI RDMA Protocol (SRP) Target driver for Linux
+=================================================
+
+The SRP Target driver is designed to work directly on top of the
+OpenFabrics OFED-1.x software stack (http://www.openfabrics.org) or
+the Infiniband drivers in the Linux kernel tree
+(http://www.kernel.org). The SRP target driver also interfaces with
+the generic SCSI target mid-level driver called SCST
+(http://scst.sourceforge.net).
+
+How-to run
+-----------
+
+A. On srp target machine
+1. Please refer to SCST's README for loading scst driver and its
+dev_handlers drivers (scst_disk, scst_vdisk block or file IO mode, nullio, ...)
+
+Example 1: working with real back-end scsi disks
+a. modprobe scst
+b. modprobe scst_disk
+c. cat /proc/scsi_tgt/scsi_tgt
+
+ibstor00:~ # cat /proc/scsi_tgt/scsi_tgt
+Device (host:ch:id:lun or name) Device handler
+0:0:0:0 dev_disk
+4:0:0:0 dev_disk
+5:0:0:0 dev_disk
+6:0:0:0 dev_disk
+7:0:0:0 dev_disk
+
+Now you want to exclude the first scsi disk and expose the last 4 scsi disks as
+IB/SRP luns for I/O
+echo "add 4:0:0:0 0" >/proc/scsi_tgt/groups/Default/devices
+echo "add 5:0:0:0 1" >/proc/scsi_tgt/groups/Default/devices
+echo "add 6:0:0:0 2" >/proc/scsi_tgt/groups/Default/devices
+echo "add 7:0:0:0 3" >/proc/scsi_tgt/groups/Default/devices
+
+Example 2: working with VDISK FILEIO mode (using md0 device and file 10G-file)
+a. modprobe scst
+b. modprobe scst_vdisk
+c. echo "open vdisk0 /dev/md0" > /proc/scsi_tgt/vdisk/vdisk
+d. echo "open vdisk1 /10G-file" > /proc/scsi_tgt/vdisk/vdisk
+e. echo "add vdisk0 0" >/proc/scsi_tgt/groups/Default/devices
+f. echo "add vdisk1 1" >/proc/scsi_tgt/groups/Default/devices
+
+Example 3: working with VDISK BLOCKIO mode (using md0 device, sda, and cciss/c1d0)
+a. modprobe scst
+b. modprobe scst_vdisk
+c. echo "open vdisk0 /dev/md0 BLOCKIO" > /proc/scsi_tgt/vdisk/vdisk
+d. echo "open vdisk1 /dev/sda BLOCKIO" > /proc/scsi_tgt/vdisk/vdisk
+e. echo "open vdisk2 /dev/cciss/c1d0 BLOCKIO" > /proc/scsi_tgt/vdisk/vdisk
+f. echo "add vdisk0 0" >/proc/scsi_tgt/groups/Default/devices
+g. echo "add vdisk1 1" >/proc/scsi_tgt/groups/Default/devices
+h. echo "add vdisk2 2" >/proc/scsi_tgt/groups/Default/devices
+
+2. modprobe ib_srpt
+
+
+B. On initiator machines you can manualy do the following steps:
+1. modprobe ib_srp
+2. ibsrpdm -c (to discover new SRP target)
+3. echo <new target info> > /sys/class/infiniband_srp/srp-mthca0-1/add_target
+4. fdisk -l (will show new discovered scsi disks)
+
+Example:
+Assume that you use port 1 of first HCA in the system ie. mthca0
+
+[root@...104 ~]# ibsrpdm -c -d /dev/infiniband/umad0
+id_ext=0002c90200226cf4,ioc_guid=0002c90200226cf4,
+dgid=fe800000000000000002c90200226cf5,pkey=ffff,service_id=0002c90200226cf4
+[root@...104 ~]# echo id_ext=0002c90200226cf4,ioc_guid=0002c90200226cf4,
+dgid=fe800000000000000002c90200226cf5,pkey=ffff,service_id=0002c90200226cf4 >
+/sys/class/infiniband_srp/srp-mthca0-1/add_target
+
+OR
+
++ You can edit /etc/infiniband/openib.conf to load srp driver and srp HA daemon
+automatically ie. set SRP_LOAD=yes, and SRPHA_ENABLE=yes
++ To set up and use high availability feature you need dm-multipath driver
+and multipath tool
++ Please refer to OFED-1.x SRP's user manual for more in-details instructions
+on how-to enable/use HA feature
+
+To minimize QUEUE_FULL conditions, you can apply scst_increase_max_tgt_cmds
+patch from SRPT package from http://sourceforge.net/project/showfiles.php?group_id=110471
+
+
+Performance notes
+-----------------
+
+In some cases, for instance working with SSD devices, which consume 100%
+of a single CPU load for data transfers in their internal threads, to
+maximize IOPS it can be needed to assign for those threads dedicated
+CPUs using Linux CPU affinity facilities. No IRQ processing should be
+done on those CPUs. Check that using /proc/interrupts. See taskset
+command and Documentation/IRQ-affinity.txt in your kernel's source tree
+for how to assign CPU affinity to tasks and IRQs.
+
+The reason for that is that processing of coming commands in SIRQ context
+can be done on the same CPUs as SSD devices' threads doing data
+transfers. As the result, those threads won't receive all the CPU power
+and perform worse.
+
+Alternatively to CPU affinity assignment, you can try to enable SRP
+target's internal thread. It will allows Linux CPU scheduler to better
+distribute load among available CPUs. To enable SRP target driver's
+internal thread you should load ib_srpt module with parameter
+"thread=1".
+
+
+Send questions about this driver to scst-devel@...ts.sourceforge.net, CC:
+Vu Pham <vuhuong@...lanox.com> and Bart Van Assche <bart.vanassche@...il.com>.
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