xref: /illumos-gate/usr/src/man/man9e/tran_dmafree.9e (revision d48be21240dfd051b689384ce2b23479d757f2d8)
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TRAN_DMAFREE 9E "Aug 30, 1995"
NAME
tran_dmafree - SCSI HBA DMA deallocation entry point
SYNOPSIS
#include <sys/scsi/scsi.h>



 void prefixtran_dmafree(struct scsi_address *ap, struct scsi_pkt *pkt);
INTERFACE LEVEL
illumos architecture specific (illumos DDI).
ARGUMENTS
ap

A pointer to a scsi_address structure. See scsi_address(9S).

pkt

A pointer to a scsi_pkt structure. See scsi_pkt(9S).

DESCRIPTION
The tran_dmafree() vector in the scsi_hba_tran structure must be initialized during the HBA driver's attach() to point to an HBA entry point to be called when a target driver calls scsi_dmafree(9F). See attach(9E) and scsi_hba_tran(9S).

tran_dmafree() must deallocate any DMA resources previously allocated to this pkt in a call to tran_init_pkt(9E). tran_dmafree() should not free the structure pointed to by pkt itself. Since tran_destroy_pkt(9E) must also free DMA resources, it is important that the HBA driver keeps accurate note of whether scsi_pkt(9S) structures have DMA resources allocated.

SEE ALSO
attach (9E), tran_destroy_pkt (9E), tran_init_pkt (9E), scsi_dmafree (9F), scsi_dmaget (9F), scsi_hba_attach (9F), scsi_init_pkt (9F), scsi_address (9S), scsi_hba_tran (9S), scsi_pkt (9S)

Writing Device Drivers

NOTES
A target driver may call tran_dmafree() on packets for which no DMA resources were allocated.