man pages section 9: DDI and DKI Kernel Functions

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Updated: July 2014
 
 

ddi_iomin(9F)

Name

ddi_iomin - find minimum alignment and transfer size for DMA

Synopsis

#include <sys/conf.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>

int ddi_iomin(dev_info_t *dip, int initial, int streaming);

Interface Level

Solaris DDI specific (Solaris DDI). This interface is obsolete.

Parameters

dip

A pointer to the device's dev_info structure.

initial

The initial minimum DMAtransfer size in bytes. This may be zero or an appropriate dlim_minxfer value for device's ddi_dma_lim structure (see ddi_dma_lim_sparc(9S) or ddi_dma_lim_x86 (9S)). This value must be a power of two.

streaming

This argument, if non-zero, indicates that the returned value should be modified to account for streaming mode accesses (see ddi_dma_req(9S) for a discussion of streaming versus non-streaming access mode).

Description

The ddi_iomin() function, finds out the minimum DMAtransfer size for the device pointed to by dip. This provides a mechanism by which a driver can determine the effects of underlying caches as well as intervening bus adapters on the granularity of a DMA transfer.

Return Values

The ddi_iomin() function returns the minimum DMAtransfer size for the calling device, or it returns zero, which means that you cannot get there from here.

Context

This function can be called from user, interrupt, or kernel context.

Attributes

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Interface Stability
Obsolete

See Also

ddi_dma_devalign(9F), ddi_dma_setup(9F), ddi_dma_sync(9F), ddi_dma_lim_sparc(9S), ddi_dma_lim_x86(9S), ddi_dma_req(9S)

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