+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ */
+
#ifndef __LNET_API_H__
#define __LNET_API_H__
-#include <lnet/types.h>
+/** \defgroup lnet LNet
+ *
+ * The Lustre Networking subsystem.
+ *
+ * LNet is an asynchronous message-passing API, which provides an unreliable
+ * connectionless service that can't guarantee any order. It supports OFA IB,
+ * TCP/IP, and Cray Portals, and routes between heterogeneous networks.
+ * @{
+ */
-int LNetInit(void);
-void LNetFini(void);
+#ifndef __KERNEL__
+# error This include is only for kernel use.
+#endif
+#include <lnet/types.h>
+
+/** \defgroup lnet_init_fini Initialization and cleanup
+ * The LNet must be properly initialized before any LNet calls can be made.
+ * @{ */
int LNetNIInit(lnet_pid_t requested_pid);
int LNetNIFini(void);
-
+/** @} lnet_init_fini */
+
+/** \defgroup lnet_addr LNet addressing and basic types
+ *
+ * Addressing scheme and basic data types of LNet.
+ *
+ * The LNet API is memory-oriented, so LNet must be able to address not only
+ * end-points but also memory region within a process address space.
+ * An ::lnet_nid_t addresses an end-point. An ::lnet_pid_t identifies a process
+ * in a node. A portal represents an opening in the address space of a
+ * process. Match bits is criteria to identify a region of memory inside a
+ * portal, and offset specifies an offset within the memory region.
+ *
+ * LNet creates a table of portals for each process during initialization.
+ * This table has MAX_PORTALS entries and its size can't be dynamically
+ * changed. A portal stays empty until the owning process starts to add
+ * memory regions to it. A portal is sometimes called an index because
+ * it's an entry in the portals table of a process.
+ *
+ * \see LNetMEAttach
+ * @{ */
int LNetGetId(unsigned int index, lnet_process_id_t *id);
int LNetDist(lnet_nid_t nid, lnet_nid_t *srcnid, __u32 *order);
-int LNetCtl(unsigned int cmd, void *arg);
-void LNetSnprintHandle (char *str, int str_len, lnet_handle_any_t handle);
-
-/*
- * Portals
- */
-int LNetSetLazyPortal(int portal);
-int LNetClearLazyPortal(int portal);
-
-/*
- * Match entries
- */
+void LNetSnprintHandle(char *str, int str_len, lnet_handle_any_t handle);
+
+/** @} lnet_addr */
+
+
+/** \defgroup lnet_me Match entries
+ *
+ * A match entry (abbreviated as ME) describes a set of criteria to accept
+ * incoming requests.
+ *
+ * A portal is essentially a match list plus a set of attributes. A match
+ * list is a chain of MEs. Each ME includes a pointer to a memory descriptor
+ * and a set of match criteria. The match criteria can be used to reject
+ * incoming requests based on process ID or the match bits provided in the
+ * request. MEs can be dynamically inserted into a match list by LNetMEAttach()
+ * and LNetMEInsert(), and removed from its list by LNetMEUnlink().
+ * @{ */
int LNetMEAttach(unsigned int portal,
lnet_process_id_t match_id_in,
__u64 match_bits_in,
lnet_handle_me_t *handle_out);
int LNetMEUnlink(lnet_handle_me_t current_in);
-
-/*
- * Memory descriptors
- */
+/** @} lnet_me */
+
+/** \defgroup lnet_md Memory descriptors
+ *
+ * A memory descriptor contains information about a region of a user's
+ * memory (either in kernel or user space) and optionally points to an
+ * event queue where information about the operations performed on the
+ * memory descriptor are recorded. Memory descriptor is abbreviated as
+ * MD and can be used interchangeably with the memory region it describes.
+ *
+ * The LNet API provides two operations to create MDs: LNetMDAttach()
+ * and LNetMDBind(); one operation to unlink and release the resources
+ * associated with a MD: LNetMDUnlink().
+ * @{ */
int LNetMDAttach(lnet_handle_me_t current_in,
lnet_md_t md_in,
lnet_unlink_t unlink_in,
lnet_handle_md_t *handle_out);
int LNetMDUnlink(lnet_handle_md_t md_in);
-
-/*
- * Event queues
- */
+/** @} lnet_md */
+
+/** \defgroup lnet_eq Events and event queues
+ *
+ * Event queues (abbreviated as EQ) are used to log operations performed on
+ * local MDs. In particular, they signal the completion of a data transmission
+ * into or out of a MD. They can also be used to hold acknowledgments for
+ * completed PUT operations and indicate when a MD has been unlinked. Multiple
+ * MDs can share a single EQ. An EQ may have an optional event handler
+ * associated with it. If an event handler exists, it will be run for each
+ * event that is deposited into the EQ.
+ *
+ * In addition to the lnet_handle_eq_t, the LNet API defines two types
+ * associated with events: The ::lnet_event_kind_t defines the kinds of events
+ * that can be stored in an EQ. The lnet_event_t defines a structure that
+ * holds the information about with an event.
+ *
+ * There are five functions for dealing with EQs: LNetEQAlloc() is used to
+ * create an EQ and allocate the resources needed, while LNetEQFree()
+ * releases these resources and free the EQ. LNetEQGet() retrieves the next
+ * event from an EQ, and LNetEQWait() can be used to block a process until
+ * an EQ has at least one event. LNetEQPoll() can be used to test or wait
+ * on multiple EQs.
+ * @{ */
int LNetEQAlloc(unsigned int count_in,
lnet_eq_handler_t handler,
lnet_handle_eq_t *handle_out);
int timeout_ms,
lnet_event_t *event_out,
int *which_eq_out);
+/** @} lnet_eq */
-/*
- * Data movement
- */
+/** \defgroup lnet_data Data movement operations
+ *
+ * The LNet API provides two data movement operations: LNetPut()
+ * and LNetGet().
+ * @{ */
int LNetPut(lnet_nid_t self,
lnet_handle_md_t md_in,
lnet_ack_req_t ack_req_in,
unsigned int portal_in,
__u64 match_bits_in,
unsigned int offset_in);
+/** @} lnet_data */
-int LNetSetAsync(lnet_process_id_t id, int nasync);
+/** \defgroup lnet_misc Miscellaneous operations.
+ * Miscellaneous operations.
+ * @{ */
-#ifndef __KERNEL__
-/* Temporary workaround to allow uOSS and test programs force server
- * mode in userspace. See comments near ln_server_mode_flag in
- * lnet/lib-types.h */
+int LNetSetLazyPortal(int portal);
+int LNetClearLazyPortal(int portal);
+int LNetCtl(unsigned int cmd, void *arg);
-void lnet_server_mode();
-#endif
+/** @} lnet_misc */
+/** @} lnet */
#endif
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