scsi_sync_pkt(9F)                                          Kernel Functions for Drivers                                          scsi_sync_pkt(9F)

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

       scsi_sync_pkt()  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_trans-
       port(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

       scsi_sync_pkt() may be called from user or interrupt 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

SunOS 5.10                                                          25 Feb 1994                                                  scsi_sync_pkt(9F)