#include <sys/conf.h> #include <sys/ddi.h> #include <sys/sunddi.h>int ddi_iomin(dev_info_t *dip, int initial, int streaming);
Solaris DDI specific (Solaris DDI).
A pointer to the device's dev_info structure.
The initial minimum DMA transfer 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_IA(9S)). This value must be a power of two.
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).
ddi_iomin(), finds out the minimum DMA transfer 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.
ddi_iomin() returns the minimum DMA transfer size for the calling device, or it returns zero, which means that you cannot get there from here.
This function can be called from user or interrupt context.