Fix locking. Use two queues in the driver, one for pending transacions, and
one for transactions which are actually running on the hardware. Call
dma_run_dependencies() on descriptor cleanup so that the async_tx API works
correctly.

There are a number of places throughout the code where lists of descriptors
are freed in a loop. Create functions to handle this, and use them instead
of open-coding the loop each time.
Signed-off-by: NIra W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This fixes some errors in the cleanup paths of the OF subsystem, including
missing checks for ioremap failing. Also, some variables were renamed for
brevity.
Signed-off-by: NIra W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Most functions in the standard library use "dst" as a parameter, rather
than "dest". This renames all use of "dest" to "dst" to match the usual
convention.
Signed-off-by: NIra W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This is the beginning of a cleanup which will change all instances of
"fsl_dma" to "fsldma" to match the name of the driver itself.
Signed-off-by: NIra W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Remove some unused members from the fsldma data structures. A few trivial
uses of struct resource were converted to use the stack rather than keeping
the memory allocated for the lifetime of the driver.
Signed-off-by: NIra W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

When using the Freescale DMA controller in external control mode, both the
request count and external pause bits need to be setup correctly. This was
being done with the same function.

The 83xx controller lacks the external pause feature, but has a similar
feature called external start. This feature requires that the request count
bits be setup correctly.

Split the function into two parts, to make it possible to use the external
start feature on the 83xx controller.
Signed-off-by: NIra W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Drop fsldma's use of tx_list from struct dma_async_tx_descriptor in
preparation for removal of this field.

Cc: Li Yang <leoli@freescale.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

By default, the Freescale 83xx DMA controller uses the PCI Read Line
command when reading data over the PCI bus. Setting the controller to use
the PCI Read Multiple command instead allows the controller to read much
larger bursts of data, which provides a drastic speed increase.

The slowdown due to using PCI Read Line was only observed when a PCI-to-PCI
bridge was between the devices trying to communicate.

A simple test driver showed an increase from 4MB/sec to 116MB/sec when
performing DMA over the PCI bus. Using DMA to transfer between blocks of
local SDRAM showed no change in performance with this patch. The dmatest
driver was also used to verify the correctness of the transfers, and showed
no errors.
Signed-off-by: NIra W. Snyder <iws@ovro.caltech.edu>
Acked-by: NTimur Tabi <timur@freescale.com>
Acked-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Modify the Freescale Elo / Elo Plus DMA driver so that it can be compiled as
a module.

The primary change is to stop treating the DMA controller as a bus, and the
DMA channels as devices on the bus.  This is because the Open Firmware (OF)
kernel code does not allow busses to be removed, so although we can call
of_platform_bus_probe() to probe the DMA channels, there is no
of_platform_bus_remove().  Instead, the DMA channels are manually probed,
similar to what fsl_elbc_nand.c does.

Cc: Scott Wood <scottwood@freescale.com>
Acked-by: NLi Yang <leoli@freescale.com>
Signed-off-by: NTimur Tabi <timur@freescale.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

 a) every bitwise declaration will give a unique type; use typedefs.

 b) no need to bother with the stuff pointed to by iomem pointers,
    unless it's accessed directly.  noderef will force us to use helpers
    anyway.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The DMA_INTERRUPT async_tx is a NULL transfer, thus the BCR(count register)
is 0. When the transfer started with a byte count of zero, the DMA
controller will triger a PE(programming error) event and halt, not a normal
interrupt. I add special codes for PE event and DMA_INTERRUPT
async_tx testing.
Signed-off-by: NZhang Wei <wei.zhang@freescale.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The driver implements DMA engine API for Freescale MPC85xx DMA controller,
which could be used by devices in the silicon.  The driver supports the
Basic mode of Freescale MPC85xx DMA controller.  The MPC85xx processors
supported include MPC8540/60, MPC8555, MPC8548, MPC8641 and so on.

The MPC83xx(MPC8349, MPC8360) are also supported.

[kamalesh@linux.vnet.ibm.com: build fix]
[dan.j.williams@intel.com: merge mm fixes, rebase on async_tx-2.6.25]
Signed-off-by: NZhang Wei <wei.zhang@freescale.com>
Signed-off-by: NEbony Zhu <ebony.zhu@freescale.com>
Acked-by: NKumar Gala <galak@gate.crashing.org>
Cc: Shannon Nelson <shannon.nelson@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>