Index for Section 9

Alphabetical listing for S

Bottom of page

sg_entry(9s)
NAME
  sg_entry - General: Contains bus address/byte count pairs

SYNOPSIS
  ________________________
  Member Name	Data Type
  ________________________
  ba		bus_addr_t
  bc		long
  ________________________

MEMBERS
  ba  Stores an I/O bus address.

  bc  Stores the byte count associated with the I/O bus address.  This byte
      count indicates the contiguous addresses that are valid on this bus.

DESCRIPTION
  The sg_entry data structure contains two members: ba and bc. These members
  represent a bus address/byte count pair for a contiguous block of an I/O
  buffer mapped onto a controller's bus memory space. The byte count
  indicates the number of bytes that the address is contiguously valid for on
  the controller's bus address space. Consider a list entry that has its ba
  member set to aaaa and its bc member set to nnnn. In this case, the device
  can perform a contiguous DMA data transfer starting at bus address aaaa and
  ending at bus address aaaa+nnnn-1.

NOTES
  The header file <devdriver.h> shows a typedef statement that assigns the
  alternate name sg_entry_t for a pointer to the sg_entry data structure.

FILES
  <io/common/devdriver.h>

SEE ALSO
  Kernel Interfaces: dma_get_curr_sgentry(9r), dma_get_next_sgentry(9r),
  dma_put_curr_sgentry(9r), dma_put_prev_sgentry(9r)

Index for Section 9

Alphabetical listing for S

Top of page