man/man9f/scsi_sync_pkt.9f

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 scsi_sync_pkt 9F "16 Jan 2006" "SunOS 5.11" "Kernel Functions for Drivers"
 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