Now that mv_xor_slot_cleanup() has no remaining callers, we remove it
and rename __mv_xor_slot_cleanup() to mv_xor_slot_cleanup().

We take this opportunity to add a comment that makes it clear that the
channel spinlock should be held before calling mv_xor_slot_cleanup().
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

In order to simplify the code, remove all the calls to the locked
mv_xor_slot_cleanup() and instead use the unlocked version only,

It's less error prone to have just one function, and require the caller
to ensure proper locking.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

In mv_xor_status(), we are currently calling mv_xor_clean_completed_slots()
when the transaction is complete (the cookie status is DMA_COMPLETE).
However, a completed status means that mv_xor_slot_cleanup() was called,
which cleans the completed slots.

In other words, there's nothing to cleanup for a completed transaction in
mv_xor_status(). Remove the unneeded call to mv_xor_clean_completed_slots().
Reported-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This commit adds proper error checking for various DMA API calls,
as reported by DMA_API_DEBUG=y.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Enabling some of the mvebu platforms in the multiplatform config for ARM
enabled these drivers, which also triggered a bunch of warnings when LPAE
is enabled (thus making phys_addr_t 64-bit).

Most changes are switching printk formats, but also a bit of changes to what
used to be array-based pointer arithmetic that could just be done with the
address types instead.

The warnings were:

drivers/dma/mv_xor.c: In function 'mv_xor_tx_submit':
drivers/dma/mv_xor.c:500:3: warning: format '%x' expects argument of type
    'unsigned int', but argument 4 has type 'dma_addr_t' [-Wformat]
drivers/dma/mv_xor.c: In function 'mv_xor_alloc_chan_resources':
drivers/dma/mv_xor.c:553:13: warning: cast to pointer from integer of
    different size [-Wint-to-pointer-cast]
drivers/dma/mv_xor.c:555:4: warning: cast from pointer to integer of
    different size [-Wpointer-to-int-cast]
drivers/dma/mv_xor.c: In function 'mv_xor_prep_dma_memcpy':
drivers/dma/mv_xor.c:584:2: warning: format '%x' expects argument of type
    'unsigned int', but argument 5 has type 'dma_addr_t' [-Wformat]
drivers/dma/mv_xor.c:584:2: warning: format '%x' expects argument of type
    'unsigned int', but argument 6 has type 'dma_addr_t' [-Wformat]
drivers/dma/mv_xor.c: In function 'mv_xor_prep_dma_xor':
drivers/dma/mv_xor.c:628:2: warning: format '%u' expects argument of type
    'unsigned int', but argument 7 has type 'dma_addr_t' [-Wformat]
Acked-by: NVinod Koul <vinod.koul@intel.com>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Signed-off-by: NOlof Johansson <olof@lixom.net>

When a channel fails to initialise, we error out and clean up any
previously unregistered channels by walking the entire xordev->channels
array.  Unfortunately, there are paths which end up storing an error
pointer in this array, which we then try and dereference in the cleanup
code, which causes an oops.

Fix this by avoiding writing invalid pointers to this array in the first
place.
Tested-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The driver-specific unmap code was removed in:

  commit 54f8d501
  Author: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
  Date:   Fri Oct 18 19:35:32 2013 +0200

      dmaengine: remove DMA unmap from drivers

which had the side-effect of not unmapping the self-test mappings.
Fix this by using dmaengine_unmap_data in the self-test routines.

In addition, since dmaengine_unmap() assumes that all mappings were created
with dma_map_page, this commit changes the single mapping to a page mapping
to avoid an incorrect unmapping of the memcpy self-test.

The allocation could be changed to be alloc_page(), but sticking to kmalloc
results in a less intrusive patch. The size of the test buffer is increased,
since dma_map_page() seem to fail when the source and destination pages are
the same page.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The following commit:

  54f8d501 dmaengine: remove DMA unmap from drivers

removed the last caller to mv_desc_get_dest_addr(), creating the
warning:

  drivers/dma/mv_xor.c:57:12: warning: mv_desc_get_dest_addr defined
  but not used [-Wunused-function]

Remove it.
Signed-off-by: NJason Cooper <jason@lakedaemon.net>
Acked-by: NVinod Koul <vinod.koul@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Despite requesting two memory resources, called 'base' and 'high_base', the
driver uses explicitly only the former. The latter is being used implicitly
by addressing at offset +0x200, which in practice accesses high_base.

In other words, the current driver breaks if the second memory resource
is ever place at an offset different from +0x200.

This patch fixes the above by defining the registers with the offset from
high_base, and use high_base explicitly where appropriate.
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This mmio address is checked at probe-time, which makes this test
redundant. Let's just remove it.
Acked-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Remove support for DMA unmapping from drivers as it is no longer
needed (DMA core code is now handling it).

Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
[djbw: fix up chan2parent() unused warning in drivers/dma/dw/core.c]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Add a hook for a common dma unmap implementation to enable removal of
the per driver custom unmap code.  (A reworked version of Bartlomiej
Zolnierkiewicz's patches to remove the custom callbacks and the size
increase of dma_async_tx_descriptor for drivers that don't care about
raid).

Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Dave Jiang <dave.jiang@intel.com>
[bzolnier: prepare pl330 driver for adding missing unmap while at it]
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Acked-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Return directly if memory allocation fails. There is no need
of dma_free_coherent().
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Cc: Saeed Bishara <saeed@marvell.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The mv_xor driver had never been used in a big-endian context, and
therefore was not using the hardware features to support such an
execution environment. The hardware provides a "descriptor swap" bit
that automatically swaps the bytes of the DMA descriptors, within
blocks of 8 bytes. This requires a different DMA descriptor layout on
big-endian systems, as well as enabling this "descriptor swap" bit.

This mechanism is exactly identical to the one already used in the
mv643xx_eth network driver and the mvneta network driver.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NDan Williams <djbw@fb.com>

In order to support big-endian execution, the mv_xor driver is changed
to use the readl_relaxed() and writel_relaxed() accessors that
properly convert from the CPU endianess to the device endianess (which
in the case of Marvell XOR hardware is always little-endian).
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NDan Williams <djbw@fb.com>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

%p is used, thus NULL should be used instead of 0
in order to fix the following sparse warning:

drivers/dma/mv_xor.c:648:9: warning: Using plain integer as NULL pointer
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

There have never been any real users of MEMSET operations since they
have been introduced in January 2007 by commit 7405f74b ("dmaengine:
refactor dmaengine around dma_async_tx_descriptor").  Therefore remove
support for them for now, it can be always brought back when needed.

[sebastian.hesselbarth@gmail.com: fix drivers/dma/mv_xor]
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Acked-by: NDan Williams <djbw@fb.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Olof Johansson <olof@lixom.net>
Cc: Kevin Hilman <khilman@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dev_<level> calls take less code than dev_printk(KERN_<LEVEL>
and reducing object size is good.
Coalesce formats for easier grep.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>

When a channel fails to initialize, we release all ressources,
including clocks. However, a XOR unit is not necessarily associated to
a clock (some variants of Marvell SoCs have a clock for XOR units,
some don't), so we shouldn't unconditionally be releasing the clock.

Instead, just like we do in the mv_xor_remove() function, we should
check if one clock was found before releasing it.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NJason Cooper <jason@lakedaemon.net>

When mv_xor_channel_add() fails for one XOR channel, we jump to the
err_channel_add label to clean up all previous channels that had been
initialized correctly. Unfortunately, while handling this error
condition, we were disposing the IRQ mapping before calling
mv_xor_channel_remove() (which does the free_irq()), which is
incorrect.

Instead, do things properly in the reverse order of the
initialization: first remove the XOR channel (so that free_irq() is
done), and then dispose the IRQ mapping.

This avoids ugly warnings when for some reason one of the XOR channel
fails to initialize.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NJason Cooper <jason@lakedaemon.net>

CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Li Yang <leoli@freescale.com>
Cc: Zhang Wei <zw@zh-kernel.org>
Cc: Barry Song <baohua.song@csr.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Acked-by: NBarry Song <baohua.song@csr.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The ->probe() function of the mv_xor function contains in its error
handling code a loop to cleanup the XOR channels that had been
successfully initialized if some other XOR channel fails to be
initialized. It does that by traveling the list of XOR channels, and
cleanup those for which the pointer is not NULL.

However, since the mv_xor_channel_add() function return a PTR_ERR
style value, the pointer is not NULL on error. So, when handling the
error of a given channel initialization, we cleanup this channel
initialization and mark this channel entry as NULL in the array. This
allows the remaining of the cleanup (for other channels) to work
properly.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

The irq_of_parse_and_map() function returns 0 on failure, and does not
return an error code, so we fix the calling site of
irq_of_parse_and_map() in the mv_xor driver.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

Even through the usage of devm_*() functions is generally recommended
over their classic variants, in the case of devm_request_irq()
combined with irq_of_parse_and_map(), it doesn't work nicely.

We have the following scenario:

 irq_of_parse_and_map(...)
 devm_request_irq(...)

For some reason, the driver initialization fails at a later
point. Since irq_of_parse_and_map() is no device-managed, we do a:

 irq_dispose_mapping(...)

Unfortunately, this doesn't work, because the free_irq() must be done
prior to calling irq_dispose_mapping(). But with the devm mechanism,
the automatic free_irq() would happen only after we get out of the
->probe() function.

So basically, we revert to using request_irq() with traditional error
handling, so that in case of error, free_irq() gets called before
irq_dispose_mapping().
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

The XOR channels on Marvell SoCs have a Window Override Control
register that allow to do some fancy things with addresses. Those
features are not used by the driver, but some U-Boot versions anyway
modify those registers.

For some reason, the U-Boot on OpenBlocks AX3-4 was setting an invalid
value in those registers when the addition 2 GB DRAM chip was plugged
into the board, causing the XOR driver to fail in using the XOR
engines.

By setting those registers to 0 during the driver initialization, we
ensure that the registers are configured according with the driver
operation model.

Thanks to Lior Amsalem <alior@marvell.com> for his help in debugging
this problem.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

The dmatest module for DMA engines calls

device_control(dtc->chan, DMA_TERMINATE_ALL, 0);

after completing the tests. The documentation in
include/linux/dmaengine.h suggests this function is optional and
dma_async_device_register() also does not BUG_ON() when not passed a
function. However, dmatest is not the only code in the kernel
unconditionally calling device_control. So add an implementation
indicating all operations are not implemented.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

The ->probe() and ->remove() functions were missing the usual
__devinit and __devexit qualifiers.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

This patch finally adds a Device Tree binding to the mv_xor
driver. Thanks to the previous cleanup patches, the Device Tree
binding is relatively simply: one DT node per XOR engine, with
sub-nodes for each XOR channel of the XOR engine. The binding
obviously comes with the necessary documentation.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: devicetree-discuss@lists.ozlabs.org

Even though the driver cannot be unloaded at the moment, it is still
good to properly free the IRQ handlers in the channel removal function.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

The pool_size is always PAGE_SIZE, and since it is a software
configuration paramter (and not a hardware description parameter), we
cannot make it part of the Device Tree binding, so we'd better remove
it from the platform_data as well.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

There is no need for the platform_data to give this ID, it is simply
the channel number, so we can compute it inside the driver when
registering the channels.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

The backpointer from mv_xor_chan to mv_xor_device is now useless, get
rid of it.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

Now that mv_xor_device is no longer used to designate the per-channel
DMA devices, use it know to designate the XOR engine themselves
(currently composed of two XOR channels).

So, now we have the nice organization where:

 - mv_xor_device represents each XOR engine in the system
 - mv_xor_chan   represents each XOR channel of a given XOR engine
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

Even though the DMA engine infrastructure has support for multiple
channels per device, the mv_xor driver registers one DMA engine device
for each channel, because the mv_xor channels inside the same XOR
engine have different capabilities, and the DMA engine infrastructure
only allows to express capabilities at the DMA engine device level.

The mv_xor driver has therefore been registering one DMA engine device
and one DMA engine channel for each XOR channel since its introduction
in the kernel. However, it kept two separate internal structures,
mv_xor_device and mv_xor_channel, which didn't make a lot of sense
since there was a 1:1 mapping between those structures.

This patch gets rid of this duplication, and merges everything into
the mv_xor_chan structure.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

In preparation for the removal of the mv_xor_device structure, we
directly pass mv_xor_chan pointers to the self-test functions included
in the driver. These functions were anyway selecting the first (and
only channel) available in each DMA device, so the behaviour is
unchanged.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

The mv_xor_device structure embeds a 'struct dma_device', which is
named 'common', a not very meaningful name. Rename it to 'dmadev',
which will help avoid confusions later as we merge the mv_xor_device
and mv_xor_chan structures together.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

The mv_xor_chan structure embeds a 'struct dma_chan', which is named
'common', a not very meaningful name. Rename it to 'dmachan', which
will help avoid confusions later as we merge the mv_xor_device and
mv_xor_chan structures together.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>