dmaengine: make clients responsible for managing channels
authorDan Williams <dan.j.williams@intel.com>
Mon, 9 Jul 2007 18:56:42 +0000 (11:56 -0700)
committerDan Williams <dan.j.williams@intel.com>
Fri, 13 Jul 2007 15:06:13 +0000 (08:06 -0700)
commitd379b01e9087a582d58f4b678208a4f8d8376fe7
tree155920bca93c18afba66b9d5acfecd359d5bec65
parent7405f74badf46b5d023c5d2b670b4471525f6c91
dmaengine: make clients responsible for managing channels

The current implementation assumes that a channel will only be used by one
client at a time.  In order to enable channel sharing the dmaengine core is
changed to a model where clients subscribe to channel-available-events.
Instead of tracking how many channels a client wants and how many it has
received the core just broadcasts the available channels and lets the
clients optionally take a reference.  The core learns about the clients'
needs at dma_event_callback time.

In support of multiple operation types, clients can specify a capability
mask to only be notified of channels that satisfy a certain set of
capabilities.

Changelog:
* removed DMA_TX_ARRAY_INIT, no longer needed
* dma_client_chan_free -> dma_chan_release: switch to global reference
  counting only at device unregistration time, before it was also happening
  at client unregistration time
* clients now return dma_state_client to dmaengine (ack, dup, nak)
* checkpatch.pl fixes
* fixup merge with git-ioat

Cc: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
drivers/dma/dmaengine.c
drivers/dma/ioatdma.c
drivers/dma/ioatdma.h
include/linux/dmaengine.h
net/core/dev.c