Drop iop-adma's use of tx_list from struct dma_async_tx_descriptor in
preparation for removal of this field.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

No drivers currently implement these operation types, so they can be
deleted.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Even though the intent is to extend dmatest with P+Q tests there is
still value in having an always-on sanity check to prevent an
unintentionally broken driver from registering.

This depends on raid6_pq.ko for verification, the side effect being that
PQ capable channels will fail to register when raid6 is disabled.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

iop33x support is not included because that engine is a bit more awkward
to handle in that it can either be in xor mode or pq mode.  The
dmaengine/async_tx layers currently only comprehend static capabilities.

Note iop13xx does not support hardware PQ continuation so the driver
must handle the DMA_PREP_CONTINUE flag for operations across > 16
sources. From the comment for dma_maxpq:

/* When an engine does not support native continuation we need 3 extra
 * source slots to reuse P and Q with the following coefficients:
 * 1/ {00} * P : remove P from Q', but use it as a source for P'
 * 2/ {01} * Q : use Q to continue Q' calculation
 * 3/ {00} * Q : subtract Q from P' to cancel (2)
 */
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

lockdep correctly identifies a potential recursive locking case for
iop_chan->lock, but in the dependency submission case we expect that the same
class will be acquired for both the parent dependency and the child channel.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Replace 'desc->async_tx.' with 'tx->'

[ Impact: pure cleanup ]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

[ Based on an original patch by Yuri Tikhonov ]

This adds support for doing asynchronous GF multiplication by adding
two additional functions to the async_tx API:

 async_gen_syndrome() does simultaneous XOR and Galois field
    multiplication of sources.

 async_syndrome_val() validates the given source buffers against known P
    and Q values.

When a request is made to run async_pq against more than the hardware
maximum number of supported sources we need to reuse the previous
generated P and Q values as sources into the next operation.  Care must
be taken to remove Q from P' and P from Q'.  For example to perform a 5
source pq op with hardware that only supports 4 sources at a time the
following approach is taken:

p, q = PQ(src0, src1, src2, src3, COEF({01}, {02}, {04}, {08}))
p', q' = PQ(p, q, q, src4, COEF({00}, {01}, {00}, {10}))

p' = p + q + q + src4 = p + src4
q' = {00}*p + {01}*q + {00}*q + {10}*src4 = q + {10}*src4

Note: 4 is the minimum acceptable maxpq otherwise we punt to
synchronous-software path.

The DMA_PREP_CONTINUE flag indicates to the driver to reuse p and q as
sources (in the above manner) and fill the remaining slots up to maxpq
with the new sources/coefficients.

Note1: Some devices have native support for P+Q continuation and can skip
this extra work.  Devices with this capability can advertise it with
dma_set_maxpq.  It is up to each driver how to handle the
DMA_PREP_CONTINUE flag.

Note2: The api supports disabling the generation of P when generating Q,
this is ignored by the synchronous path but is implemented by some dma
devices to save unnecessary writes.  In this case the continuation
algorithm is simplified to only reuse Q as a source.

Cc: H. Peter Anvin <hpa@zytor.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NYuri Tikhonov <yur@emcraft.com>
Signed-off-by: NIlya Yanok <yanok@emcraft.com>
Reviewed-by: NAndre Noll <maan@systemlinux.org>
Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

'zero_sum' does not properly describe the operation of generating parity
and checking that it validates against an existing buffer.  Change the
name of the operation to 'val' (for 'validate').  This is in
anticipation of the p+q case where it is a requirement to identify the
target parity buffers separately from the source buffers, because the
target parity buffers will not have corresponding pq coefficients.
Reviewed-by: NAndre Noll <maan@systemlinux.org>
Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Centralize this common initialization (and one case where ipu_idmac is
duplicating ->chan initialization).
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

iop_adma_zero_sum_self_test has the brackets in the wrong place for the
setup failure deallocation path.  This error was duplicated in
mv_xor_xor_self_test.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

`iop_adma_remove' referenced in section `.data' of drivers/built-in.o: defined in discarded section `.devexit.text' of drivers/built-in.o
`mv_xor_remove' referenced in section `.data' of drivers/built-in.o: defined in discarded section `.devexit.text' of drivers/built-in.o
`mv64xxx_i2c_unmap_regs' referenced in section `.devinit.text' of drivers/built-in.o: defined in discarded section `.devexit.text' of drivers/built-in.o
`mv64xxx_i2c_remove' referenced in section `.data' of drivers/built-in.o: defined in discarded section `.devexit.text' of drivers/built-in.o
`orion_nand_remove' referenced in section `.data' of drivers/built-in.o: defined in discarded section `.devexit.text' of drivers/built-in.o
`pxafb_remove' referenced in section `.data' of drivers/built-in.o: defined in discarded section `.devexit.text' of drivers/built-in.o
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

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

No need to free stuff that the devm infrastructure will take care of...
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Reference counting is done at the module level so clients need not worry
that a channel will leave while they are actively using dmaengine.
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

All users have been converted to either the general-purpose allocator,
dma_find_channel, or dma_request_channel.
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

async_tx.ko is a consumer of dma channels.  A circular dependency arises
if modules in drivers/dma rely on common code in async_tx.ko.  It
prevents either module from being unloaded.

Move dma_wait_for_async_tx and async_tx_run_dependencies to dmaeninge.o
where they should have been from the beginning.
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Mapping the destination multiple times is a misuse of the dma-api.
Since the destination may be reused as a source, ensure that it is only
mapped once and that it is mapped bidirectionally.  This appears to add
ugliness on the unmap side in that it always reads back the destination
address from the descriptor, but gcc can determine that dma_unmap is a
nop and not emit the code that calculates its arguments.

Cc: <stable@kernel.org>
Cc: Saeed Bishara <saeed@marvell.com>
Acked-by: NYuri Tikhonov <yur@emcraft.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Now that the critical read back to flush the next descriptor address is
fixed we can downgrade some BUG_ONs that need only be enabled when testing
changes to the driver.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The current dummy read references the wrong address allowing the next
descriptor address update to linger in the store buffer and get passed
by an 'append' event.

This issue was uncovered by the change from strongly-ordered to device
memory for the adma registers.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This just leaves include/asm-arm/plat-* to deal with.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

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

Force callers that trigger an "out of descriptors" condition to run the
cleanup loop directly.  Alleviates the requirement to have soft-irqs
enabled when polling for a descriptor in async_xor.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

In some cases client code may need the dma-driver to skip the unmap of source
and/or destination buffers.  Setting these flags indicates to the driver to
skip the unmap step.  In this regard async_xor is currently broken in that it
allows the destination buffer to be unmapped while an operation is still in
progress, i.e. when the number of sources exceeds the hardware channel's
maximum (fixed in a subsequent patch).
Acked-by: NSaeed Bishara <saeed@marvell.com>
Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

A DMA controller capable of doing slave transfers may need to know a
few things about the slave when preparing the channel. We don't want
to add this information to struct dma_channel since the channel hasn't
yet been bound to a client at this point.

Instead, pass a reference to the client requesting the channel to the
driver's device_alloc_chan_resources hook so that it can pick the
necessary information from the dma_client struct by itself.

[dan.j.williams@intel.com: fixed up fsldma and mv_xor]
Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Since 43cc71ee, the platform
modalias is prefixed with "platform:". Add MODULE_ALIAS() to most
of the hotpluggable platform drivers, to re-enable auto loading.

Cc: <stable@kernel.org>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

1) Remove an explicit memset(.., 0, ...) to a variable allocated with
kzalloc (i.e. 'dest').

2) Allocate 'src' with kmalloc instead of kzalloc as all elements of the
'src' buffer are initialized in a 'for(...)' loop just after.

3) remove useless 'sizeof(u8)', which always returns 1, when computing the
size of the memory to be allocated.
Signed-off-by: NChristophe Jaillet <christophe.jaillet@wanadoo.fr>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

'ack' is currently a simple integer that flags whether or not a client is done
touching fields in the given descriptor.  It is effectively just a single bit
of information.  Converting this to a flags parameter allows the other bits to
be put to use to control completion actions, like dma-unmap, and capture
results, like xor-zero-sum == 0.

Changes are one of:
1/ convert all open-coded ->ack manipulations to use async_tx_ack
   and async_tx_test_ack.
2/ set the ack bit at prep time where possible
3/ make drivers store the flags at prep time
4/ add flags to the device_prep_dma_interrupt prototype
Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This workaround was covering the dependency submission bug in async_tx.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

DMA drivers no longer need to be notified of dependency submission
events as async_tx_run_dependencies and async_tx_channel_switch will
handle the scheduling and execution of dependent operations.

[sfr@canb.auug.org.au: extend this for fsldma]
Acked-by: NShannon Nelson <shannon.nelson@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Shrink struct dma_async_tx_descriptor and introduce
async_tx_channel_switch to properly inject a channel switch interrupt in
the descriptor stream.  This simplifies the locking model as drivers no
longer need to handle dma_async_tx_descriptor.lock.
Acked-by: NShannon Nelson <shannon.nelson@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Pass a full set of flags to drivers' per-operation 'prep' routines.
Currently the only flag passed is DMA_PREP_INTERRUPT.  The expectation is
that arch-specific async_tx_find_channel() implementations can exploit this
capability to find the best channel for an operation.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NShannon Nelson <shannon.nelson@intel.com>
Reviewed-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>

The tx_set_src and tx_set_dest methods were originally implemented to allow
an array of addresses to be passed down from async_xor to the dmaengine
driver while minimizing stack overhead.  Removing these methods allows
drivers to have all transaction parameters available at 'prep' time, saves
two function pointers in struct dma_async_tx_descriptor, and reduces the
number of indirect branches..

A consequence of moving this data to the 'prep' routine is that
multi-source routines like async_xor need temporary storage to convert an
array of linear addresses into an array of dma addresses.  In order to keep
the same stack footprint of the previous implementation the input array is
reused as storage for the dma addresses.  This requires that
sizeof(dma_addr_t) be less than or equal to sizeof(void *).  As a
consequence CONFIG_DMADEVICES now depends on !CONFIG_HIGHMEM64G.  It also
requires that drivers be able to make descriptor resources available when
the 'prep' routine is polled.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NShannon Nelson <shannon.nelson@intel.com>

these three list_head are all local variables, but can also use LIST_HEAD.
Signed-off-by: NDenis Cheng <crquan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Adrian Bunk points out that "unsafe" was used to mark modules touched by
the deprecated MOD_INC_USE_COUNT interface, which has long gone.  It's time
to remove the member from the module structure, as well.

If you want a module which can't unload, don't register an exit function.

(Vlad Yasevich says SCTP is now safe to unload, so just remove the
__unsafe there).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NShannon Nelson <shannon.nelson@intel.com>
Acked-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Cc: Sridhar Samudrala <sri@us.ibm.com>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The Intel(R) IOP series of i/o processors integrate an Xscale core with
raid acceleration engines.  The capabilities per platform are:

iop219:
 (2) copy engines
iop321:
 (2) copy engines
 (1) xor and block fill engine
iop33x:
 (2) copy and crc32c engines
 (1) xor, xor zero sum, pq, pq zero sum, and block fill engine
iop34x (iop13xx):
 (2) copy, crc32c, xor, xor zero sum, and block fill engines
 (1) copy, crc32c, xor, xor zero sum, pq, pq zero sum, and block fill engine

The driver supports the features of the async_tx api:
* asynchronous notification of operation completion
* implicit (interupt triggered) handling of inter-channel transaction
  dependencies

The driver adapts to the platform it is running by two methods.
1/ #include <asm/arch/adma.h> which defines the hardware specific
   iop_chan_* and iop_desc_* routines as a series of static inline
   functions
2/ The private platform data attached to the platform_device defines the
   capabilities of the channels

20070626: Callbacks are run in a tasklet.  Given the recent discussion on
LKML about killing tasklets in favor of workqueues I did a quick conversion
of the driver.  Raid5 resync performance dropped from 50MB/s to 30MB/s, so
the tasklet implementation remains until a generic softirq interface is
available.

Changelog:
* fixed a slot allocation bug in do_iop13xx_adma_xor that caused too few
slots to be requested eventually leading to data corruption
* enabled the slot allocation routine to attempt to free slots before
returning -ENOMEM
* switched the cleanup routine to solely use the software chain and the
status register to determine if a descriptor is complete.  This is
necessary to support other IOP engines that do not have status writeback
capability
* make the driver iop generic
* modified the allocation routines to understand allocating a group of
slots for a single operation
* added a null xor initialization operation for the xor only channel on
iop3xx
* support xor operations on buffers larger than the hardware maximum
* split the do_* routines into separate prep, src/dest set, submit stages
* added async_tx support (dependent operations initiation at cleanup time)
* simplified group handling
* added interrupt support (callbacks via tasklets)
* brought the pending depth inline with ioat (i.e. 4 descriptors)
* drop dma mapping methods, suggested by Chris Leech
* don't use inline in C files, Adrian Bunk
* remove static tasklet declarations
* make iop_adma_alloc_slots easier to read and remove chances for a
  corrupted descriptor chain
* fix locking bug in iop_adma_alloc_chan_resources, Benjamin Herrenschmidt
* convert capabilities over to dma_cap_mask_t
* fixup sparse warnings
* add descriptor flush before iop_chan_enable
* checkpatch.pl fixes
* gpl v2 only correction
* move set_src, set_dest, submit to async_tx methods
* move group_list and phys to async_tx

Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>