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scsi_resalloc(9f) [bsd man page]

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

NAME
scsi_pktalloc, scsi_resalloc, scsi_pktfree, scsi_resfree - SCSI packet utility routines SYNOPSIS
#include <sys/scsi/scsi.h> struct scsi_pkt *scsi_pktalloc(struct scsi_address*ap, intcmdlen, intstatuslen, int(*callback )(void)); struct scsi_pkt *scsi_resalloc(struct scsi_address*ap, intcmdlen, intstatuslen, opaque_tdmatoken, int(*callback )(void)); voidscsi_pktfree(struct scsi_pkt*pkt); voidscsi_resfree(struct scsi_pkt*pkt); INTERFACE LEVEL
The scsi_pktalloc(), scsi_pktfree(), scsi_resalloc(), and scsi_resfree() functions are obsolete. The scsi_pktalloc() and scsi_resalloc() functions have been replaced by scsi_init_pkt(9F). The scsi_pktfree() and scsi_resfree() functions have been replaced by scsi_destroy_pkt(9F). PARAMETERS
ap Pointer to a scsi_address structure. cmdlen The required length for the SCSI command descriptor block (CDB) in bytes. statuslen The required length for the SCSI status completion block (SCB) in bytes. dmatoken Pointer to an implementation-dependent object. callback A pointer to a callback function, or NULL_FUNC or SLEEP_FUNC. pkt Pointer to a scsi_pkt(9S) structure. DESCRIPTION
scsi_pktalloc() requests the host adapter driver to allocate a command packet. For commands that have a data transfer associated with them, scsi_resalloc() should be used. ap is a pointer to a scsi_address structure. Allocator routines use it to determine the associated host adapter. cmdlen is the required length for the SCSI command descriptor block. This block is allocated such that a kernel virtual address is estab- lished in the pkt_cdbp field of the allocated scsi_pkt structure. statuslen is the required length for the SCSI status completion block. The address of the allocated block is placed into the pkt_scbp field of the scsi_pkt structure. dmatoken is a pointer to an implementation dependent object which defines the length, direction, and address of the data transfer associ- ated with this SCSI packet (command). The dmatoken must be a pointer to a buf(9S) structure. If dmatoken is NULL, no DMA resources are required by this SCSI command, so none are allocated. Only one transfer direction is allowed per command. If there is an unexpected data transfer phase (either no data transfer phase expected, or the wrong direction encountered), the command is terminated with the pkt_reason set to CMD_DMA_DERR. dmatoken provides the information to determine if the transfer count is correct. callback indicates what the allocator routines should do when resources are not available: NULL_FUNC Do not wait for resources. Return a NULL pointer. SLEEP_FUNC Wait indefinitely for resources. Other Values callback points to a function which is called when resources may have become available. callback must return either 0 (indicating that it attempted to allocate resources but again failed to do so), in which case it is put back on a list to be called again later, or 1 indicating either success in allocating resources or indicating that it no longer cares for a retry. scsi_pktfree() frees the packet. scsi_resfree() free all resources held by the packet and the packet itself. RETURN VALUES
Both allocation routines return a pointer to a scsi_pkt structure on success, or NULL on failure. CONTEXT
If callback is SLEEP_FUNC, then this routine may only be called from user-level code. Otherwise, it may be called from either user or interrupt level. The callback function may not block or call routines that block. Both deallocation routines can be called from user or interrupt context. ATTRIBUTES
See attributes(5) for a description of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Stability Level |Obsolete | +-----------------------------+-----------------------------+ SEE ALSO
attributes(5), scsi_dmafree(9F), scsi_dmaget(9F), buf(9S), scsi_pkt(9S) Writing Device Drivers NOTES
The scsi_pktalloc(), scsi_pktfree(), scsi_resalloc(), and scsi_resfree() functions are obsolete and will be discontinued in a future release. The scsi_pktalloc() and scsi_resalloc() functions have been replaced by scsi_init_pkt(9F). The scsi_pktfree() and scsi_resfree() functions have been replaced by scsi_destroy_pkt(9F). SunOS 5.10 27 Sep 2002 scsi_pktalloc(9F)

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