ddi_dma_nextseg man page on OpenIndiana

Man page or keyword search:  
man Server   20441 pages
apropos Keyword Search (all sections)
Output format
OpenIndiana logo
[printable version]

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

NAME
       ddi_dma_nextseg - get next DMA segment

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

       int ddi_dma_nextseg(ddi_dma_win_t win, ddi_dma_seg_t seg,
	    ddi_dma_seg_t *nseg);

INTERFACE LEVEL
       This  interface	is  obsolete.  ddi_dma_nextcookie(9F)  should  be used
       instead.

PARAMETERS
       win     A DMA window.

       seg     The current DMA segment or NULL.

       nseg    A pointer to the next DMA segment to be filled in.  If  seg  is
	       NULL,  a pointer to the first segment within the specified win‐
	       dow is returned.

DESCRIPTION
       The ddi_dma_nextseg() function gets the next  DMA  segment  within  the
       specified  window  win.	If  the current segment is NULL, the first DMA
       segment within the window is returned.

       A DMA segment is always required for a DMA window.  A DMA segment is  a
       contiguous  portion of a DMA window (see	 ddi_dma_nextwin(9F)) which is
       entirely addressable by the device for a data transfer operation.

       An example where multiple DMA segments are allocated is where the  sys‐
       tem  does  not contain DVMA capabilities and the object may be non-con‐
       tiguous. In this example the object will be broken  into	 smaller  con‐
       tiguous DMA segments. Another example is where the device has  an upper
       limit on its transfer size (for example an 8-bit address register)  and
       has    expressed	   this	   in	 the	DMA   limit   structure	  (see
       ddi_dma_lim_sparc(9S) or	 ddi_dma_lim_x86(9S)).	In  this  example  the
       object will be broken into smaller addressable DMA segments.

RETURN VALUES
       The ddi_dma_nextseg() function returns:

       DDI_SUCCESS	Successfully filled in the next segment pointer.

       DDI_DMA_DONE	There  is  no next segment. The current segment is the
			final segment within the specified window.

       DDI_DMA_STALE	win does not refer to the currently active window.

CONTEXT
       The ddi_dma_nextseg() function can be called from user,	interrupt,  or
       kernel context.

EXAMPLES
       For an example, see ddi_dma_segtocookie(9F).

ATTRIBUTES
       See attributes(5) for a description of the following attributes:

       ┌─────────────────────────────┬─────────────────────────────┐
       │      ATTRIBUTE TYPE	     │	    ATTRIBUTE VALUE	   │
       ├─────────────────────────────┼─────────────────────────────┤
       │Interface Stability	     │Obsolete			   │
       └─────────────────────────────┴─────────────────────────────┘

SEE ALSO
       attributes(5),	   ddi_dma_addr_setup(9F),	ddi_dma_buf_setup(9F),
       ddi_dma_nextcookie(9F),	ddi_dma_nextwin(9F),  ddi_dma_segtocookie(9F),
       ddi_dma_sync(9F),      ddi_dma_lim_sparc(9S),	  ddi_dma_lim_x86(9S),
       ddi_dma_req(9S)

       Writing Device Drivers

SunOS 5.11			  04 Apr 2006		   ddi_dma_nextseg(9F)
[top]

List of man pages available for OpenIndiana

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net