When dma_addr_t is 64 bits long, compilation of the AMBA PL08x DMA
driver breaks due to a missing 64bit%8bit modulo operation.
Looking more closely the divisor in these operations can only be
1, 2 or 4, so the full featured '%' modulo operation is overkill and
can be replaced with simple bit masking.

Change from v1:
Replace open-coded function with existing IS_ALIGNED macro and use a
macro around that to avoid a line becoming too long.
Signed-off-by: NAndre Przywara <andre.przywara@linaro.org>
Acked-by: NVinod Koul <vinod.koul@intel.com>
Signed-off-by: NRob Herring <rob.herring@calxeda.com>

As pointed out by Arnd Bergmann there is a get_signal macro definied in
linux/signal.h which can conflict with the platform data callback
function of the same name leading to confusing errors from the compiler
(especially if signal.h manages to get pulled into the driver itself due
to header dependencies).  Avoid such errors by renaming get_signal and
put_signal in the platform data to get_xfer_signal and put_xfer_signal.
Signed-off-by: NMark Brown <broonie@linaro.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The header is used by drivers/dma/amba-pl08x.c, which can be compiled
under x86, where PL080 exists under a PCI-to-AMBA bridge. This patche
moves it where it can be accessed by other architectures, and fixes
all users.
Signed-off-by: NAlessandro Rubini <rubini@gnudd.com>
Acked-by: NGiancarlo Asnaghi <giancarlo.asnaghi@st.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

vchan_dma_desc_free_list() iterates through each virt_dma_desc in the
specified list_head and calls vchan->desc_free().

We can use it instead of repeated execution of pl08x_desc_free() for each
virt_dma_desc in the list_head.  Because vchan->desc_free callback is set
as pl08x_desc_free() for amba-pl08x driver.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <djbw@fb.com>
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>

Convert a 0 error return code to a negative one, as returned elsewhere in the
function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier ret;
expression e,e1,e2,e3,e4,x;
@@

(
if (\(ret != 0\|ret < 0\) || ...) { ... return ...; }
|
ret = 0
)
... when != ret = e1
*x = \(kmalloc\|kzalloc\|kcalloc\|devm_kzalloc\|ioremap\|ioremap_nocache\|devm_ioremap\|devm_ioremap_nocache\)(...);
... when != x = e2
    when != ret = e3
*if (x == NULL || ...)
{
  ... when != ret = e4
*  return ret;
}
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>

Ensure all queued descriptors are freed when the channel is released,
ensuring we don't leak memory
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The free function says the pl08x lock should be taken before calling
it.  However, the DMA pool allocation/freeing is already properly
locked.  The only thing that would need this is pool_ctr, which
happens to be a write-only variable.

Let's get rid of this, and eliminate any need for additional locking
here.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This function is now unnecessary; we can move its internals inline
instead.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Now that we're converted to use the generic vchan support, we can fix
the residue return from tx_status to be compliant with dmaengine.  This
returns the number of bytes remaining for the _specified_ cookie, not
the number of bytes in all pending transfers on the channel.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Convert to use the virtual dma channel done list, tasklet, and
descriptor freeing.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Convert to use the virtual dma channel submitted/issued descriptor
lists rather than our own private lists, and use the virtual dma
channel support functions to manage these lists.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Initialize the vchan struct, and use the provided spinlock rather than
our own.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Convert PL08x to use the virt-dma structures.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Rework the physical channel allocation mechanism to only allocate
physical channels to virtual channels when they're about to be used.
This eliminates all the complexity with holding channels while
descriptors are being prepared, which is completely unnecessary.

This also brings this driver to a state where the generic virtual DMA
code can be used with this driver, and opens up the possibility of
properly scheduling and prioritorising physical DMA channels to
virtual DMA channels.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Rather than waiting for the tasklet to run, we can start the next
descriptor from interrupt context, as soon as we know that the
previous descriptor has completed.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Our behaviour wasn't correct; issue_pending is supposed to be called
before any submitted descriptors are available for processing by the
DMA engine.  Split the pend_list in two, one for submitted descriptors
and another list for issued descriptors.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Rather than code the de-queue of the txd several times, move that into
the start_txd function.  Rename this to better illustrate what it's
now doing, and call this function when starting a delayed memcpy().
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

As we no longer need to pass a descriptor to prep_phy_channel(), we
don't need to keep track of the descriptor which is waiting for a
channel to become available.  So let's get rid of it.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Move the DMA request muxing into the slave prepare code and txd
release/completion code.  This means we only hold the DMA request
mux while there are descriptors waiting to be started or are in
progress.

This leaves txd->direction as a write-only variable; remove it.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Convert PL08x to use a list of completed descriptors rather than
merely relying upon a single pointer.  This makes it possible to
schedule the tasklet for other purposes, and makes our behaviour
similar to virt-dma.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Keep track of the number of descriptors currently using a MUX setting
on a per-channel basis.  This allows us to know when we have descriptors
queued somewhere which have been assigned a DMA request signal.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Move the signal handling out of the physical channel structure into
the virtual channel structure, where it should belong as it has more
to do with the virtual channel than the physical one.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Split the DMA request mux signal handling from the physical channel
allocation code.  The physical channel has very little to do with the
DMA request input which will be used, so these should be two separate
operations.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Get rid of the unnecessary checks in dma_slave_config utilizing
the DMA direction.  This allows us to move the computation of
cctl to the prepare function.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Ignore the direction argument in dma_slave_config, and configure both
directions independently.  We still check that the configuration for
the intended direction is valid; this check will eventually be dropped.
This check is just for debugging at present.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Extract the functionality from dma_slave_config to generate the cctl
values for a given bus width and burst size.  This allows us to use
this elsewhere in the driver, namely the prepare functions.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Move the bus and transfer increment selection to the DMA prepare
function rather than the slave configuration function.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

As we now store the dma_slave_config in pl08x_dma_chan, we don't need
to store this separately.  Use the one in dma_slave_config directly.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Add a dma_slave_config struct to struct pl08x_dma_chan, and move the
src_addr/dst_addr arguments into this struct.  This is a step away
from using the dma_slave_config's direction member.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Move the driver private data structures into the driver itself, rather
than having them exposed to everyone in a header file.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Try to avoid dereferencing the DMA engine's channel struct in these
platform helpers; instead, pass a pointer to the channel data into
get_signal(), and the returned signal number to put_signal().
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Circular buffers are not handled in this way; we have a separate API
call now to setup circular buffers.  So lets not mislead people with
this bool.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The pl08x_driver_data spinlock is only ever initialized.  Nothing else
uses it.  Let's get rid of it.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

db8196df (dmaengine: move drivers to dma_transfer_direction) missed
fixing up the "DMA_NONE" case.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The runtime PM support conflicts with the generic AMBA bus PM, and also
causes a potential deadlock with the PL011 driver as it results in
interrupts being enabled beneath a spinlock.

I don't presently see any solution to this other than by removing the
runtime PM support entirely from the DMA engine driver.  Alternative
suggestions welcome.
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

sg->length may or may not contain the length of the dma region to transfer,
depending on the architecture - dma_sg_len(sg) always will though. For the
architectures which use the drivers modified by this patch it probably is the
case that sg->length contains the dma transfer length. But to be consistent and
future proof change them to use dma_sg_len.

To quote Russel King:
	sg->length is meaningless to something performing DMA.

	In cases where sg_dma_len(sg) and sg->length are the same storage, then
	there's no problem. But scatterlists _can_ (and one some architectures) do
	split them - especially when you have an IOMMU which can allow you to
	combine a scatterlist into fewer entries.

	So, anything using sg->length for the size of a scatterlist's DMA transfer
	_after_ a call to dma_map_sg() is almost certainly buggy.

The patch has been generated using the following coccinelle patch:
<smpl>
@@
struct scatterlist *sg;
expression X;
@@
-sg[X].length
+sg_dma_len(&sg[X])
@@
struct scatterlist *sg;
@@
-sg->length
+sg_dma_len(sg)
</smpl>
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>

dmaengine drivers should always use sg_dma_address instead of sg_phys to get the
addresses for the transfer from a sg element.

To quote Russel King:
	sg_phys(sg) of course has nothing to do with DMA addresses. It's the
	physical address _to the CPU_ of the memory associated with the scatterlist
	entry. That may, or may not have the same value for the DMA engine,
	particularly if IOMMUs are involved.

	And if these drivers are used on ARM, they must be fixed, sooner rather
	than later.  There's patches in the works which will mean we will end up
	with IOMMU support in the DMA mapping later, which means everything I've
	said above will become reality.

The patch has been generated using the following coccinelle patch:
<smpl>
@@
struct scatterlist *sg;
@@
-sg_phys(sg)
+sg_dma_address(sg)
</smpl>
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>

The Nomadik PL080 variant has some extra protection bits that
may be set, so we need to check these bits to see if the
channels are actually available for the DMAengine to use.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Alim Akhtar <alim.akhtar@gmail.com>
Cc: Alessandro Rubini <rubini@gnudd.com>
Reviewed-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>

When a client calls pl08x_control with DMA_TERMINATE_ALL, it is correct
to terminate and release the phy channel currently in use (if one is in use),
but the phychan_hold counter must also be reset (otherwise it could get
trapped in an unbalanced state).
Signed-off-by: NDavide Ciminaghi <ciminaghi@gnudd.com>
Reviewed-by: NViresh Kumar <viresh.kumar@st.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>