In the multiple device case we need to re-arm the completion and protect
against concurrent self-tests.  The printk from the test callback is
removed as it can arbitrarily delay completion of the test.

Cc: <stable@kernel.org>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

There are dmaengine users that would like to register dma devices at
subsys_initcall time to ensure channels are available by device_initcall
time.

Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Allow dma_filter_fn routines to disambiguate multiple channels on a device
rather than assuming that all channels on a device are equal.

Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Reported-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

This brings some predictability to dma device numbers, i.e. an rmmod/insmod
cycle may now result in /sys/class/dma/dma0chan0 being restored rather than
/sys/class/dma/dma1chan0 appearing.

Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Resolves:
WARNING: at drivers/base/core.c:122 device_release+0x4d/0x52()
Device 'dma0chan0' does not have a release() function, it is broken and must be fixed.

The dma_chan_dev object is introduced to gear-match sysfs kobject and
dmaengine channel lifetimes.  When a channel is removed access to the
sysfs entries return -ENODEV until the kobject can be released.

The bulk of the change is updates to existing code to handle the extra
layer of indirection between a dma_chan and its struct device.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Unregistering services should only happen at "remove" time.  This prevents
the device from being unregistered while dmaengine clients are still
active.  Also, the comment on ioat_remove is stale since removal is prevented
while a channel may be in use.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

This BUG_ON caught problems in early development but now it is in the
way as it invalidly triggers when trying to remove the module.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

No need to free stuff that the devm infrastructure will take care of...

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

DMA_NAK is now useless.  We can just use a bool instead.

Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>