man/man3rsm/rsm_memseg_import_putv.3rsm

         te
 Copyright (c) 2001 by Sun Microsystems, Inc. All rights reserved.
 The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
 You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
 When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
 RSM_MEMSEG_IMPORT_PUTV 3RSM "Nov 12, 2001"
 NAME
rsm_memseg_import_putv, rsm_memseg_import_getv - write to a segment using a
list of I/O requests
 SYNOPSIS

cc [ flag... ] file... -lrsm [ library... ]
#include <rsmapi.h>

int rsm_memseg_import_putv(rsm_scat_gath_t *sg_io);


int rsm_memseg_import_getv(rsm_scat_gath_t *sg_io);


 DESCRIPTION

The rsm_memseg_import_putv() and rsm_memseg_import_getv() functions
provide for using a list of I/O requests rather than a single source and
destination address as is done for the rsm_memseg_import_put(3RSM) and
rsm_memseg_import_get(3RSM) functions.

The I/O vector component of the scatter-gather list (sg_io), allows
specifying local virtual addresses or local_memory_handles. When a local
address range is used repeatedly, it is efficient to use a handle because
allocated system resources (that is, locked down local memory) are maintained
until the handle is freed. The supporting functions for handles are
rsm_create_localmemory_handle(3RSM) and
rsm_free_localmemory_handle(3RSM).

Virtual addresses or handles may be gathered into the vector for writing to a
single remote segment, or a read from a single remote segment may be scattered
to the vector of virtual addresses or handles.

Implicit mapping is supported for the scatter-gather type of access. The
attributes of the extension library for the specific interconnect are used to
determine whether mapping is necessary before any scatter-gather access. If
mapping of the imported segment is a prerequisite for scatter-gather access and
the mapping has not already been performed, an implicit mapping is performed
for the imported segment. The I/O for the vector is then initiated.

I/O for the entire vector is initiated before returning. The barrier mode
attribute of the import segment determines if the I/O has completed before the
function returns. A barrier mode attribute setting of IMPLICIT
guarantees that the transfer of data is completed in the order as entered in
the I/O vector. An implicit barrier open and close surrounds each list entry.
If an error is detected, I/O for the vector is terminated and the function
returns immediately. The residual count indicates the number of entries for
which the I/O either did not complete or was not initiated.

The number of entries in the I/O vector component of the scatter-gather list is
specified in the io_request_count field of the rsm_scat_gath_t
pointed to by sg_io. The io_request_count is valid if greater than
0 and less than or equal to RSM_MAX_SGIOREQS. If io_request_count
is not in the valid range, rsm_memseg_import_putv() and
rsm_memseg_import_getv() returns RSMERR_BAD_SGIO.

Optionally, the scatter-gather list allows support for an implicit signal post
after the I/O for the entire vector has completed. This alleviates the need to
do an explicit signal post after ever I/O transfer operation. The means of
enabling the implicit signal post involves setting the flags field within
the scatter-gather list to RSM_IMPLICIT_SIGPOST. The flags field
may also be set to RSM_SIG_POST_NO_ACCUMULATE, which will be passed on to
the signal post operation when RSM_IMPLICIT_SIGPOST is set.
 RETURN VALUES

Upon successful completion, these functions return 0. Otherwise, an error value
is returned to indicate the error.
 ERRORS

The rsm_memseg_import_putv() and rsm_memseg_import_getv() functions
can return the following errors:
RSMERR_BAD_SGIO

Invalid scatter-gather structure pointer.


RSMERR_BAD_SEG_HNDL

Invalid segment handle.


RSMERR_BAD_CTLR_HNDL

Invalid controller handle.


RSMERR_BAD_OFFSET

Invalid offset.


RSMERR_BAD_LENGTH

Invalid length.


RSMERR_BAD_ADDR

Bad address.


RSMERR_INSUFFICIENT_RESOURCES

Insufficient resources.


RSMERR_INTERRUPTED

The operation was interrupted by a signal.


RSMERR_PERM_DENIED

Permission denied.


RSMERR_BARRIER_FAILURE

I/O completion error.


RSMERR_REMOTE_NODE_UNREACHABLE

Remote node not reachable.


 ATTRIBUTES

See attributes(5) for descriptions of the following attributes:


ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Evolving
MT-Level MT-Safe


 SEE ALSO

rsm_create_localmemory_handle(3RSM),
rsm_free_localmemory_handle(3RSM), attributes(5)