- No more distinction between i/o-mapped and memory-mapped
devices. It's all "bus space" now, and space tags
differentiate the space with finer grain than the
bus chipset tag.
- Add memory barrier methods.
- Implement space alloc/free methods.
- Implement region read/write methods (like memcpy to/from
bus space).
This interface provides a better abstraction for dealing with
machine-independent chipset drivers.
- merged multiple DRQ/DTQ ADD macros into a single DRQ and a single DTQ
macro with a uniform interface to make the code simpler and easier to read.
- en_start: only update atm_flags if EN_MBUF_OPT is enabled (which it
should be)
- for alburst: make sure we don't DMA more bytes than we need (on both
tx and rx). if the alburst is larger than we need, drop to
MIDDMA_WORD mode.
- major change: enable the use of byte and 2 byte DMA on the trasmit side.
this allows us to DMA from non-word sized/aligned mbufs directly.
[the old code would always call en_mfix which would copy (or move) the
data in order to ensure proper alignment... it turns out TCP gives
us non-word sized/aligned mbufs when it is retransmitting, so we needed
to handle this case more efficiently.] the following functions
were changed to make this work:
- en_dqneed: add an arg to let us know if we are transmitting or not.
if we are TX, then we must take into account byte DMAs when
estimating the number of DTQs we will need for a buffer
- en_start: only mfix mbufs if DMA is disabled
- en_txdma: only set launch.nodma if we have en_mfix'd the mbuf chain
also, we may need a DTQ to flush the chip's internal byte buffer
- en_txlaunch: only attempt a copy if we have the proper alignment.
add byte dma code for the front and end of the buffer.
make sure the internal dma buffer is flushed out.
- stats: keep track of how many times we have to use byte sized DMA
midwayreg:
- add byte/2byte DMA defines
midwayvar:
- add new stat counter to monitor less-than-word lengthed DMA
- en_mfix shouldn't touch M_EXT mbufs. change to avoid this [at
the expense of allocating a new cluster mbuf to copy to].
XXX: en_mfix is getting called more often than I hoped it would
(seems to happen when TCP retransmits... we get all sorts of odd
sized, odd lengthed data mbufs, yuck). i may revise the xmit
DMA code to use non-word sized dma.
to ignore inbound data sizes less than the threshold. otherwise,
when connected to a video aal0 input the driver gives us a massive
stream of 56 byte mbufs each with one aal0 cell in it and the
system just can't keep up with it, especially if the socket buffer
size is large [it hangs until you turn off the video source].
fixes: when turning off a vc, try and check the freshest copy of the mode
when seeing if we need to enter the "drain" state. also, don't
panic if we get unexpected rx interrupt on a VCI (instead make sure
the VC is off, print a warning, and move on!).
- change rxso into a void handle ... no need to know details at this low
level.
fix:
- forgot to init "vci" during ENOTHER_DRAIN case of RX DMA interrupt
[could cause a vm_fault on native mode connection close depending
on needing to drain out the VC and also the random value of vci]
- more stat counters (rxmbufout -- mbufs, ttrash -- trashed RBD)
- add swsl_size to keep track of size of software slist
- revise when we call en_service
- fix handling of circular lists (was getting full vs empty confused in
extreem cases...)
- native mode atm: remove sbappend code: can't do it here since
socket buffer is protected only by splsoftnet and that doesn't
mask enintr off. forces us to switch to a two level interrupt
scheme. revise call to atm_input to reflect that.
chuck