Kernel Functions for Drivers                        ddiiomin(9F)



NAME
     ddiiomin - find minimum alignment and transfer size for DMA

SYNOPSIS
     #include 
     #include 
     #include 



     int ddiiomin(devinfot *dip, int initial, int streaming);


INTERFACE LEVEL
     Solaris  DI  specific  (Solaris  DI).  This  interface  is
     obsolete.

PARAMETERS
     dip          A pointer to the device's devinfo structure.


     initial      The initial minimum DMAtransfer size in  bytes.
                  This may be zero or an appropriate dlimminxfer
                  value for device's ddidmalim  structure  (see
                  ddidmalimsparc(9S)  or ddidmalimx86(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
                  ddidmareq(9S)  for  a discussion of streaming
                  versus non-streaming access mode).


DESCRIPTION
     The ddiiomin() 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 ddiiomin() 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.





SunOS 5.11          Last change: 04 Apr 2006                    1






Kernel Functions for Drivers                        ddiiomin(9F)



ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Obsolete                    
    


SEE ALSO
     ddidmadevalign(9F),  ddidmasetup(9F),  ddidmasync(9F),
     ddidmalimsparc(9S), ddidmalimx86(9S), ddidmareq(9S)


     Writing Device Drivers




































SunOS 5.11          Last change: 04 Apr 2006                    2