ib_srpt: Initial SRP Target merge for v3.3-rc1

This patch adds the kernel module ib_srpt SCSI RDMA Protocol (SRP) target
implementation conforming to the SRP r16a specification for the mainline
drivers/target infrastructure.

This driver was originally developed by Vu Pham and has been optimized by
Bart Van Assche and merged into upstream LIO based on his srpt-lio-4.1
branch here:

   https://github.com/bvanassche/srpt-lio/commits/srpt-lio-4.1/

This updated patch also contains the following two changes from
lio-core-2.6.git/master.  One is to fix a bug with 1 >= task->task_sg[]
chained mappings in ib_srpt, and the other to convert the configfs control
plane to reference IB Port GUID and struct srpt_port directly following
mainline v4.x target_core_fabric_configfs.c convertion for ib_srpt
to work with rtslib/rtsadmin v2 code.

These seperate patches can be found here:

ib_srpt: Fix bug with chainged SGLs in srpt_map_sg_to_ib_sge
http://www.risingtidesystems.com/git/?p=lio-core-2.6.git;a=commitdiff;h=ea485147563b6555a97dbf811825fbb586519252

ib_srpt: Convert se_wwn endpoint reference to struct srpt_port->port_wwn
http://www.risingtidesystems.com/git/?p=lio-core-2.6.git;a=commitdiff;h=4e544a210acb227df1bb4ca5086e65bdf4e648ea

This also includes the following recent v1 -> v2 review changes:

ib_srpt: Fix potential out-of-bounds array access
ib_srpt: Avoid failed multipart RDMA transfers
ib_srpt: Fix srpt_alloc_fabric_acl failure case return value
ib_srpt: Update comments to reference $driver/$port layout
ib_srpt: Fix sport->port_guid formatting code
ib_srpt: Remove legacy use_port_guid_in_session_name module parameter
ib_srpt: Convert srp_max_rdma_size into per port configfs attribute
ib_srpt: Convert srp_max_rsp_size into per port configfs attribute
ib_srpt: Convert srpt_sq_size into per port configfs attribute

and v2 -> v3 review changes:

ib_srpt: Fix possible race with srp_sq_size in srpt_create_ch_ib
ib_srpt: Fix possible race with srp_max_rsp_size in srpt_release_channel_work
ib_srpt: Fix up MAX_SRPT_RDMA_SIZE define
ib_srpt: Make srpt_map_sg_to_ib_sge() failure case return -EAGAIN
ib_srpt: Convert port_guid to use subnet_prefix + interface_id formatting
ib_srpt: Make srpt_check_stop_free return kref_put status
ib_srpt: Make compilation with BUG=n proceed`
ib_srpt: Use new target_core_fabric.h include
ib_srpt: Check hex2bin() return code to silence build warning

Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Vu Pham <vu@mellanox.com>
Cc: David Dillow <dillowda@ornl.gov>
Signed-off-by: Nicholas A. Bellinger <nab@risingtidesystems.com>

1 files changed, 444 insertions, 0 deletions

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.h b/drivers/infiniband/ulp/srpt/ib_srpt.h
new file mode 100644
index 00000000000..b4b4bbcd7f1
--- /dev/null
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.h
@@ -0,0 +1,444 @@
+/*
+ * Copyright (c) 2006 - 2009 Mellanox Technology Inc.  All rights reserved.
+ * Copyright (C) 2009 - 2010 Bart Van Assche <bvanassche@acm.org>.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+#ifndef IB_SRPT_H
+#define IB_SRPT_H
+
+#include <linux/version.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/wait.h>
+
+#include <rdma/ib_verbs.h>
+#include <rdma/ib_sa.h>
+#include <rdma/ib_cm.h>
+
+#include <scsi/srp.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 specification.
+ */
+#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 specification.
+         */
+        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
+         * specification.
+         */
+        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 SRP specification.
+         */
+        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 SRP specification.
+         */
+        SRP_SOLNT = 0x01, /* SOLNT = solicited notification */
+
+        /* See also table 24 in the SRP specification. */
+        SRP_TSK_MGMT_SUCCESS = 0x00,
+        SRP_TSK_MGMT_FUNC_NOT_SUPP = 0x04,
+        SRP_TSK_MGMT_FAILED = 0x05,
+
+        /* See also table 21 in the SRP specification. */
+        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,
+        MAX_SRPT_RDMA_SIZE = 1U << 24,
+        MAX_SRPT_RSP_SIZE = 1024,
+
+        MIN_MAX_REQ_SIZE = 996,
+        DEFAULT_MAX_REQ_SIZE
+                = sizeof(struct srp_cmd)/*48*/
+                + sizeof(struct srp_indirect_buf)/*20*/
+                + 128 * sizeof(struct srp_direct_buf)/*16*/,
+
+        MIN_MAX_RSP_SIZE = sizeof(struct srp_rsp)/*36*/ + 4,
+        DEFAULT_MAX_RSP_SIZE = 256, /* leaves 220 bytes for sense data */
+
+        DEFAULT_MAX_RDMA_SIZE = 65536,
+};
+
+enum srpt_opcode {
+        SRPT_RECV,
+        SRPT_SEND,
+        SRPT_RDMA_MID,
+        SRPT_RDMA_ABORT,
+        SRPT_RDMA_READ_LAST,
+        SRPT_RDMA_WRITE_LAST,
+};
+
+static inline u64 encode_wr_id(u8 opcode, u32 idx)
+{
+        return ((u64)opcode << 32) | idx;
+}
+static inline enum srpt_opcode opcode_from_wr_id(u64 wr_id)
+{
+        return wr_id >> 32;
+}
+static inline u32 idx_from_wr_id(u64 wr_id)
+{
+        return (u32)wr_id;
+}
+
+struct rdma_iu {
+        u64             raddr;
+        u32             rkey;
+        struct ib_sge   *sge;
+        u32             sge_cnt;
+        int             mem_id;
+};
+
+/**
+ * enum srpt_command_state - SCSI command state 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:          Processing a SCSI task management command.
+ * @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          = 4,
+        SRPT_STATE_MGMT_RSP_SENT = 5,
+        SRPT_STATE_DONE          = 6,
+};
+
+/**
+ * struct srpt_ioctx - Shared SRPT I/O context information.
+ * @buf:   Pointer to the buffer.
+ * @dma:   DMA address of the buffer.
+ * @index: Index of the I/O context in its ioctx_ring array.
+ */
+struct srpt_ioctx {
+        void                    *buf;
+        dma_addr_t              dma;
+        uint32_t                index;
+};
+
+/**
+ * struct srpt_recv_ioctx - SRPT receive I/O context.
+ * @ioctx:     See above.
+ * @wait_list: Node for insertion in srpt_rdma_ch.cmd_wait_list.
+ */
+struct srpt_recv_ioctx {
+        struct srpt_ioctx       ioctx;
+        struct list_head        wait_list;
+};
+
+/**
+ * struct srpt_send_ioctx - SRPT send I/O context.
+ * @ioctx:       See above.
+ * @ch:          Channel pointer.
+ * @free_list:   Node in srpt_rdma_ch.free_list.
+ * @n_rbuf:      Number of data buffers in the received SRP command.
+ * @rbufs:       Pointer to SRP data buffer array.
+ * @single_rbuf: SRP data buffer if the command has only a single buffer.
+ * @sg:          Pointer to sg-list associated with this I/O context.
+ * @sg_cnt:      SG-list size.
+ * @mapped_sg_count: ib_dma_map_sg() return value.
+ * @n_rdma_ius:  Number of elements in the rdma_ius array.
+ * @rdma_ius:    Array with information about the RDMA mapping.
+ * @tag:         Tag of the received SRP information unit.
+ * @spinlock:    Protects 'state'.
+ * @state:       I/O context state.
+ * @rdma_aborted: If initiating a multipart RDMA transfer failed, whether
+ *               the already initiated transfers have finished.
+ * @cmd:         Target core command data structure.
+ * @sense_data:  SCSI sense data.
+ */
+struct srpt_send_ioctx {
+        struct srpt_ioctx       ioctx;
+        struct srpt_rdma_ch     *ch;
+        struct kref              kref;
+        struct rdma_iu          *rdma_ius;
+        struct srp_direct_buf   *rbufs;
+        struct srp_direct_buf   single_rbuf;
+        struct scatterlist      *sg;
+        struct list_head        free_list;
+        spinlock_t              spinlock;
+        enum srpt_command_state state;
+        bool                    rdma_aborted;
+        struct se_cmd           cmd;
+        struct completion       tx_done;
+        u64                     tag;
+        int                     sg_cnt;
+        int                     mapped_sg_count;
+        u16                     n_rdma_ius;
+        u8                      n_rdma;
+        u8                      n_rbuf;
+        bool                    queue_status_only;
+        u8                      sense_data[SCSI_SENSE_BUFFERSIZE];
+};
+
+/**
+ * enum rdma_ch_state - SRP channel state.
+ * @CH_CONNECTING:       QP is in RTR state; waiting for RTU.
+ * @CH_LIVE:             QP is in RTS state.
+ * @CH_DISCONNECTING:    DREQ has been received; waiting for DREP
+ *                       or DREQ has been send and waiting for DREP
+ *                       or .
+ * @CH_DRAINING:         QP is in ERR state; waiting for last WQE event.
+ * @CH_RELEASING:        Last WQE event has been received; releasing resources.
+ */
+enum rdma_ch_state {
+        CH_CONNECTING,
+        CH_LIVE,
+        CH_DISCONNECTING,
+        CH_DRAINING,
+        CH_RELEASING
+};
+
+/**
+ * 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.
+ * @qp:            IB queue pair used for communicating over this channel.
+ * @cq:            IB completion queue for this channel.
+ * @rq_size:       IB receive queue size.
+ * @rsp_size       IB response message size in bytes.
+ * @sq_wr_avail:   number of work requests available in the send queue.
+ * @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.
+ * @req_lim:       request limit: maximum number of requests that may be sent
+ *                 by the initiator without having received a response.
+ * @req_lim_delta: Number of credits not yet sent back to the initiator.
+ * @spinlock:      Protects free_list and state.
+ * @free_list:     Head of list with free send I/O contexts.
+ * @state:         channel state. See also enum rdma_ch_state.
+ * @ioctx_ring:    Send ring.
+ * @wc:            IB work completion array for srpt_process_completion().
+ * @list:          Node for insertion in the srpt_device.rch_list list.
+ * @cmd_wait_list: List of SCSI 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.
+ * @sess:          Session information associated with this SRP channel.
+ * @sess_name:     Session name.
+ * @release_work:  Allows scheduling of srpt_release_channel().
+ * @release_done:  Enables waiting for srpt_release_channel() completion.
+ */
+struct srpt_rdma_ch {
+        wait_queue_head_t       wait_queue;
+        struct task_struct      *thread;
+        struct ib_cm_id         *cm_id;
+        struct ib_qp            *qp;
+        struct ib_cq            *cq;
+        int                     rq_size;
+        u32                     rsp_size;
+        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                req_lim;
+        atomic_t                req_lim_delta;
+        spinlock_t              spinlock;
+        struct list_head        free_list;
+        enum rdma_ch_state      state;
+        struct srpt_send_ioctx  **ioctx_ring;
+        struct ib_wc            wc[16];
+        struct list_head        list;
+        struct list_head        cmd_wait_list;
+        struct se_session       *sess;
+        u8                      sess_name[36];
+        struct work_struct      release_work;
+        struct completion       *release_done;
+};
+
+/**
+ * struct srpt_port_attib - Attributes for SRPT port
+ * @srp_max_rdma_size: Maximum size of SRP RDMA transfers for new connections.
+ * @srp_max_rsp_size: Maximum size of SRP response messages in bytes.
+ * @srp_sq_size: Shared receive queue (SRQ) size.
+ */
+struct srpt_port_attrib {
+        u32                     srp_max_rdma_size;
+        u32                     srp_max_rsp_size;
+        u32                     srp_sq_size;
+};
+
+/**
+ * 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.
+ * @enabled:   Whether or not this target port is enabled.
+ * @port_guid: ASCII representation of Port GUID
+ * @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.
+ * @port_acl_lock spinlock for port_acl_list:
+ * @work:      work structure for refreshing the aforementioned cached values.
+ * @port_tpg_1 Target portal group = 1 data.
+ * @port_wwn:  Target core WWN data.
+ * @port_acl_list: Head of the list with all node ACLs for this port.
+ */
+struct srpt_port {
+        struct srpt_device      *sdev;
+        struct ib_mad_agent     *mad_agent;
+        bool                    enabled;
+        u8                      port_guid[64];
+        u8                      port;
+        u16                     sm_lid;
+        u16                     lid;
+        union ib_gid            gid;
+        spinlock_t              port_acl_lock;
+        struct work_struct      work;
+        struct se_portal_group  port_tpg_1;
+        struct se_wwn           port_wwn;
+        struct list_head        port_acl_list;
+        struct srpt_port_attrib port_attrib;
+};
+
+/**
+ * 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.
+ * @srq_size:      SRQ size.
+ * @ioctx_ring:    Per-HCA SRQ.
+ * @rch_list:      Per-device channel list -- see also srpt_rdma_ch.list.
+ * @ch_releaseQ:   Enables waiting for removal from rch_list.
+ * @spinlock:      Protects rch_list and tpg.
+ * @port:          Information about the ports owned by this HCA.
+ * @event_handler: Per-HCA asynchronous IB event handler.
+ * @list:          Node in srpt_dev_list.
+ */
+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_recv_ioctx  **ioctx_ring;
+        struct list_head        rch_list;
+        wait_queue_head_t       ch_releaseQ;
+        spinlock_t              spinlock;
+        struct srpt_port        port[2];
+        struct ib_event_handler event_handler;
+        struct list_head        list;
+};
+
+/**
+ * struct srpt_node_acl - Per-initiator ACL data (managed via configfs).
+ * @i_port_id: 128-bit SRP initiator port ID.
+ * @sport:     port information.
+ * @nacl:      Target core node ACL information.
+ * @list:      Element of the per-HCA ACL list.
+ */
+struct srpt_node_acl {
+        u8                      i_port_id[16];
+        struct srpt_port        *sport;
+        struct se_node_acl      nacl;
+        struct list_head        list;
+};
+
+/*
+ * SRP-releated SCSI persistent reservation definitions.
+ *
+ * See also SPC4r28, section 7.6.1 (Protocol specific parameters introduction).
+ * See also SPC4r28, section 7.6.4.5 (TransportID for initiator ports using
+ * SCSI over an RDMA interface).
+ */
+
+enum {
+        SCSI_TRANSPORTID_PROTOCOLID_SRP = 4,
+};
+
+struct spc_rdma_transport_id {
+        uint8_t protocol_identifier;
+        uint8_t reserved[7];
+        uint8_t i_port_id[16];
+};
+
+#endif                          /* IB_SRPT_H */