cvs commit: src/sys/dev/gem if_gem.c if_gemreg.h if_gemvar.h

[Pyun YongHyeon]

yongari     2007-06-04 06:01:04 UTC

  FreeBSD src repository

  Modified files:
    sys/dev/gem          if_gem.c if_gemreg.h if_gemvar.h 
  Log:
  o Implemented Rx/Tx checksum offload. The simple checksum logic in
    GEMs is unable to discriminate UDP from TCP packets such that
    it can generate 0x0000 checksum value for the UDP datagram. So the
    UDP checksum offload was disabled by default. You can enable it
    by setting link0 flag with ifconfig(8).
  o bus_dma(9) clean up. It now correctly set number of required DMA
    segments/size and removed incorrect use of BUS_DMA_ALLOCNOW flag
    in static allocations done via bus_dmamem_alloc(9).
  o Implemented ALTQ(9) support.
  o Implemented Tx side bus_dmamap_load_mbuf_sg(9) which can remove
    several book keeping chores orginated from call-back mechanism.
    Therefore gem_txdma_callback() was removed and its functionality
    was reimplemented in gem_load_txmbuf().
  o Don't set GEM_TD_START_OF_PACKET flag until all remaining mbuf
    chains are set. I think it was a long standing bug and it caused
    fluctuating interrupts/CPU usage patterns while netperf test
    is in progress. Previously it seems that we race with the device.
    Because I don't have a documentation for GEM I'm not sure this is
    correct but almost all other documentations I have stated this
    implications on setting SOP mark in descriptor ring(e.g. hme(4)).
  o Borrowed gem_defrag() from ath(4) which is supposed to be much
    faster than m_defrag(9) since it's not need to defrag all
    mbuf chains.
  o gem_load_txmbuf() was changed to allow passed mbuf chains to free.
    Caller of gem_load_txmbuf() correctly handles freed mbuf chains.
  o In gem_start_locked(), added checks for availability of Tx
    descriptors before trying to load DMA maps which could save CPU
    cycles when number of available descriptors are low. Also, simplyfy
    IFF_DRV_OACTIVE detection logic.
  o Removed hard-coded function names in CTR macros and replaced it
    with __func__.
  o Moved statistics counter register access to gem_tick() to reduce
    number of PCI bus accesses. There is no reason to update statistics
    counters in interrupt handler.
  o Removed unnecessary call of gem_start_locked() in gem_ioctl().
  
  Reviewed by:    grehan (initial version), marius (with improvements and suggestions)
  Tested by:      grehan (ppc), marius(sparc64)
  
  Revision  Changes    Path
  1.42      +417 -218  src/sys/dev/gem/if_gem.c
  1.4       +2 -0      src/sys/dev/gem/if_gemreg.h
  1.14      +1 -6      src/sys/dev/gem/if_gemvar.h