cvs commit: src/sys/alpha/alpha busdma_machdep.c

[John Baldwin]

jhb         2007-11-27 17:43:50 UTC

  FreeBSD src repository

  Modified files:        (Branch: RELENG_6)
    sys/alpha/alpha      busdma_machdep.c 
  Log:
  Cleanup the alpha bus dma code a bit and sync it up with i386.  Changes
  include:
  - Honor alignment and boundary restrictions on DMA tags by using bounce
    pages for misaligned buffers and not coalescing pages if the resulting
    segment would cross a boundary.
  - Teach the _bus_dmamap_load_buffer() helper function to use bounce pages
    when needed and change bus_dmamap_load() to use the helper function
    instead of largely duplicating it.  As a side effect, this enables bounce
    page support for the other load routines (load_mbuf(), load_mbuf_sg(),
    and load_uio()).
  
  Honoring the boundary restrictions partially helps with the Alpha ATA DMA
  problem.  More work is needed for that however (and forthcoming).
  
  PR:             alpha/75317
  Tested by:      wilko
  Approved by:    re (kensmith)
  
  Revision  Changes    Path
  1.51.2.2  +155 -158  src/sys/alpha/alpha/busdma_machdep.c