drivers/staging/lustre/include/linux/lnet/api.h

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011 - 2015, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Seagate, Inc.
  31  */
  32
  33 #ifndef __LNET_API_H__
  34 #define __LNET_API_H__
  35
  36 /** \defgroup lnet LNet
  37  *
  38  * The Lustre Networking subsystem.
  39  *
  40  * LNet is an asynchronous message-passing API, which provides an unreliable
  41  * connectionless service that can't guarantee any order. It supports OFA IB,
  42  * TCP/IP, and Cray Interconnects, and routes between heterogeneous networks.
  43  *
  44  * @{
  45  */
  46
  47 #include "../lnet/types.h"
  48
  49 /** \defgroup lnet_init_fini Initialization and cleanup
  50  * The LNet must be properly initialized before any LNet calls can be made.
  51  * @{
  52  */
  53 int LNetNIInit(lnet_pid_t requested_pid);
  54 int LNetNIFini(void);
  55 /** @} lnet_init_fini */
  56
  57 /** \defgroup lnet_addr LNet addressing and basic types
  58  *
  59  * Addressing scheme and basic data types of LNet.
  60  *
  61  * The LNet API is memory-oriented, so LNet must be able to address not only
  62  * end-points but also memory region within a process address space.
  63  * An ::lnet_nid_t addresses an end-point. An ::lnet_pid_t identifies a process
  64  * in a node. A portal represents an opening in the address space of a
  65  * process. Match bits is criteria to identify a region of memory inside a
  66  * portal, and offset specifies an offset within the memory region.
  67  *
  68  * LNet creates a table of portals for each process during initialization.
  69  * This table has MAX_PORTALS entries and its size can't be dynamically
  70  * changed. A portal stays empty until the owning process starts to add
  71  * memory regions to it. A portal is sometimes called an index because
  72  * it's an entry in the portals table of a process.
  73  *
  74  * \see LNetMEAttach
  75  * @{
  76  */
  77 int LNetGetId(unsigned int index, struct lnet_process_id *id);
  78 int LNetDist(lnet_nid_t nid, lnet_nid_t *srcnid, __u32 *order);
  79
  80 /** @} lnet_addr */
  81
  82 /** \defgroup lnet_me Match entries
  83  *
  84  * A match entry (abbreviated as ME) describes a set of criteria to accept
  85  * incoming requests.
  86  *
  87  * A portal is essentially a match list plus a set of attributes. A match
  88  * list is a chain of MEs. Each ME includes a pointer to a memory descriptor
  89  * and a set of match criteria. The match criteria can be used to reject
  90  * incoming requests based on process ID or the match bits provided in the
  91  * request. MEs can be dynamically inserted into a match list by LNetMEAttach()
  92  * and LNetMEInsert(), and removed from its list by LNetMEUnlink().
  93  * @{
  94  */
  95 int LNetMEAttach(unsigned int      portal,
  96                  struct lnet_process_id match_id_in,
  97                  __u64             match_bits_in,
  98                  __u64             ignore_bits_in,
  99                  enum lnet_unlink unlink_in,
 100                  enum lnet_ins_pos pos_in,
 101                  struct lnet_handle_me *handle_out);
 102
 103 int LNetMEInsert(struct lnet_handle_me current_in,
 104                  struct lnet_process_id match_id_in,
 105                  __u64             match_bits_in,
 106                  __u64             ignore_bits_in,
 107                  enum lnet_unlink unlink_in,
 108                  enum lnet_ins_pos position_in,
 109                  struct lnet_handle_me *handle_out);
 110
 111 int LNetMEUnlink(struct lnet_handle_me current_in);
 112 /** @} lnet_me */
 113
 114 /** \defgroup lnet_md Memory descriptors
 115  *
 116  * A memory descriptor contains information about a region of a user's
 117  * memory (either in kernel or user space) and optionally points to an
 118  * event queue where information about the operations performed on the
 119  * memory descriptor are recorded. Memory descriptor is abbreviated as
 120  * MD and can be used interchangeably with the memory region it describes.
 121  *
 122  * The LNet API provides two operations to create MDs: LNetMDAttach()
 123  * and LNetMDBind(); one operation to unlink and release the resources
 124  * associated with a MD: LNetMDUnlink().
 125  * @{
 126  */
 127 int LNetMDAttach(struct lnet_handle_me current_in,
 128                  struct lnet_md md_in,
 129                  enum lnet_unlink unlink_in,
 130                  struct lnet_handle_md *md_handle_out);
 131
 132 int LNetMDBind(struct lnet_md md_in,
 133                enum lnet_unlink unlink_in,
 134                struct lnet_handle_md *md_handle_out);
 135
 136 int LNetMDUnlink(struct lnet_handle_md md_in);
 137 /** @} lnet_md */
 138
 139 /** \defgroup lnet_eq Events and event queues
 140  *
 141  * Event queues (abbreviated as EQ) are used to log operations performed on
 142  * local MDs. In particular, they signal the completion of a data transmission
 143  * into or out of a MD. They can also be used to hold acknowledgments for
 144  * completed PUT operations and indicate when a MD has been unlinked. Multiple
 145  * MDs can share a single EQ. An EQ may have an optional event handler
 146  * associated with it. If an event handler exists, it will be run for each
 147  * event that is deposited into the EQ.
 148  *
 149  * In addition to the lnet_handle_eq, the LNet API defines two types
 150  * associated with events: The ::lnet_event_kind_t defines the kinds of events
 151  * that can be stored in an EQ. The lnet_event defines a structure that
 152  * holds the information about with an event.
 153  *
 154  * There are five functions for dealing with EQs: LNetEQAlloc() is used to
 155  * create an EQ and allocate the resources needed, while LNetEQFree()
 156  * releases these resources and free the EQ. LNetEQGet() retrieves the next
 157  * event from an EQ, and LNetEQWait() can be used to block a process until
 158  * an EQ has at least one event. LNetEQPoll() can be used to test or wait
 159  * on multiple EQs.
 160  * @{
 161  */
 162 int LNetEQAlloc(unsigned int       count_in,
 163                 lnet_eq_handler_t  handler,
 164                 struct lnet_handle_eq *handle_out);
 165
 166 int LNetEQFree(struct lnet_handle_eq eventq_in);
 167
 168 int LNetEQPoll(struct lnet_handle_eq *eventqs_in,
 169                int               neq_in,
 170                int               timeout_ms,
 171                struct lnet_event *event_out,
 172                int              *which_eq_out);
 173 /** @} lnet_eq */
 174
 175 /** \defgroup lnet_data Data movement operations
 176  *
 177  * The LNet API provides two data movement operations: LNetPut()
 178  * and LNetGet().
 179  * @{
 180  */
 181 int LNetPut(lnet_nid_t        self,
 182             struct lnet_handle_md md_in,
 183             lnet_ack_req_t    ack_req_in,
 184             struct lnet_process_id target_in,
 185             unsigned int      portal_in,
 186             __u64             match_bits_in,
 187             unsigned int      offset_in,
 188             __u64             hdr_data_in);
 189
 190 int LNetGet(lnet_nid_t        self,
 191             struct lnet_handle_md md_in,
 192             struct lnet_process_id target_in,
 193             unsigned int      portal_in,
 194             __u64             match_bits_in,
 195             unsigned int      offset_in);
 196 /** @} lnet_data */
 197
 198 /** \defgroup lnet_misc Miscellaneous operations.
 199  * Miscellaneous operations.
 200  * @{
 201  */
 202 int LNetSetLazyPortal(int portal);
 203 int LNetClearLazyPortal(int portal);
 204 int LNetCtl(unsigned int cmd, void *arg);
 205 void LNetDebugPeer(struct lnet_process_id id);
 206
 207 /** @} lnet_misc */
 208
 209 /** @} lnet */
 210 #endif