node_map_pfn_alignment(9) [centos man page]

NODE_MAP_PFN_ALIGNME(9) 				    Memory Management in Linux					   NODE_MAP_PFN_ALIGNME(9)

NAME

       node_map_pfn_alignment - determine the maximum internode alignment

SYNOPSIS

       unsigned long node_map_pfn_alignment(void);

ARGUMENTS

       void
	   no arguments

DESCRIPTION

       This function should be called after node map is populated and sorted. It calculates the maximum power of two alignment which can
       distinguish all the nodes.

       For example, if all nodes are 1GiB and aligned to 1GiB, the return value would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If
       the nodes are shifted by 256MiB, 256MiB. Note that if only the last node is shifted, 1GiB is enough and this function will indicate so.

       This is used to test whether pfn -> nid mapping of the chosen memory model has fine enough granularity to avoid incorrect mapping for the
       populated node map.

       Returns the determined alignment in pfn's. 0 if there is no alignment requirement (single node).

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						   NODE_MAP_PFN_ALIGNME(9)

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

NAME

       ddi_dma_devalign - find DMA mapping alignment and minimum transfer size

SYNOPSIS

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

       int ddi_dma_devalign(ddi_dma_handle_t handle, uint_t *alignment, uint_t *minxfr);

INTERFACE LEVEL

       Solaris DDI specific (Solaris DDI).

PARAMETERS

       handle	       The DMA handle filled in by a successful call to ddi_dma_setup(9F).

       alignment       A  pointer  to an unsigned integer to be filled in with the minimum required alignment for DMA. The alignment is guaranteed
		       to be a power of two.

       minxfr	       A pointer to an	unsigned  integer  to  be  filled  in  with  the  minimum  effective  transfer	size  (see  ddi_iomin(9F),
		       ddi_dma_lim_sparc(9S) and ddi_dma_lim_x86(9S)).	This also is guaranteed to be a power of two.

DESCRIPTION

       ddi_dma_devalign()  determines  after  a successful DMA mapping (see ddi_dma_setup(9F)) the minimum required data alignment and minimum DMA
       transfer size.

RETURN VALUES

       ddi_dma_devalign() returns:

       DDI_SUCCESS     The alignment and minxfr values have been filled.

       DDI_FAILURE     The handle was illegal.

CONTEXT

       ddi_dma_devalign() can be called from user or interrupt context.

SEE ALSO

       ddi_dma_setup(9F), ddi_iomin(9F), ddi_dma_lim_sparc(9S), ddi_dma_lim_x86(9S), ddi_dma_req(9S)

       Writing Device Drivers

SunOS 5.10							    1 Feb 1994						      ddi_dma_devalign(9F)