xref: /titanic_50/usr/src/man/man9f/scsi_sync_pkt.9f (revision 7b07063d906859b2be1e88791f801b3c96e432f6)
te
Copyright (c) 2006, 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]
SCSI_SYNC_PKT 9F "Jan 16, 2006"
NAME
scsi_sync_pkt - synchronize CPU and I/O views of memory
SYNOPSIS

#include <sys/scsi/scsi.h>



void scsi_sync_pkt(struct scsi_pkt *pktp);
INTERFACE LEVEL

Solaris DDI specific (Solaris DDI).

PARAMETERS
pktp

Pointer to a scsi_pkt(9S) structure.

DESCRIPTION

The scsi_sync_pkt() function is used to selectively synchronize a CPU's or device's view of the data associated with the SCSI packet that has been mapped for I/O. This may involve operations such as flushes of CPU or I/O caches, as well as other more complex operations such as stalling until hardware write buffers have drained.

This function need only be called under certain circumstances. When a SCSI packet is mapped for I/O using scsi_init_pkt(9F) and destroyed using scsi_destroy_pkt(9F), then an implicit scsi_sync_pkt() will be performed. However, if the memory object has been modified by either the device or a CPU after the mapping by scsi_init_pkt(9F), then a call to scsi_sync_pkt() is required.

If the same scsi_pkt is reused for a data transfer from memory to a device, then scsi_sync_pkt() must be called before calling scsi_transport(9F). If the same packet is reused for a data transfer from a device to memory scsi_sync_pkt() must be called after the completion of the packet but before accessing the data in memory.

CONTEXT

The scsi_sync_pkt() function may be called from user, interrupt, or kernel context.

SEE ALSO

tran_sync_pkt(9E), ddi_dma_sync(9F), scsi_destroy_pkt(9F), scsi_init_pkt(9F), scsi_transport(9F), scsi_pkt(9S)

Writing Device Drivers