Commit Graph

67 Commits

Author SHA1 Message Date
Linus Walleij c156d0a5b0 DMAENGINE: generic slave channel control v3
This adds an interface to the DMAengine to make it possible to
reconfigure a slave channel at runtime. We add a few foreseen
config parameters to the passed struct, with a void * pointer
for custom per-device or per-platform runtime slave data.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-08-04 14:13:02 -07:00
Dan Williams 0b28330e39 Merge branch 'ioat' into dmaengine 2010-05-17 16:30:58 -07:00
Linus Walleij 058276303d DMAENGINE: extend the control command to include an arg
This adds an argument to the DMAengine control function, so that
we can later provide control commands that need some external data
passed in through an argument akin to the ioctl() operation
prototype.

[dan.j.williams@intel.com: fix up some missed conversions]
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-17 16:30:42 -07:00
Dan Williams caa20d974c async_tx: trim dma_async_tx_descriptor in 'no channel switch' case
Saves 24 bytes per descriptor (64-bit) when the channel-switching
capabilities of async_tx are not required.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-17 16:24:16 -07:00
Dan Williams bca3469205 dmaengine: provide helper for setting txstate
Simple conditional struct filler to cut out some duplicated code.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-26 16:52:10 -07:00
Linus Walleij 0793448187 DMAENGINE: generic channel status v2
Convert the device_is_tx_complete() operation on the
DMA engine to a generic device_tx_status()operation which
can return three states, DMA_TX_RUNNING, DMA_TX_COMPLETE,
DMA_TX_PAUSED.

[dan.j.williams@intel.com: update for timberdale]
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Li Yang <leoli@freescale.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Magnus Damm <damm@opensource.se>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Joe Perches <joe@perches.com>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-26 16:50:49 -07:00
Linus Walleij c3635c78e5 DMAENGINE: generic slave control v2
Convert the device_terminate_all() operation on the
DMA engine to a generic device_control() operation
which can now optionally support also pausing and
resuming DMA on a certain channel. Implemented for the
COH 901 318 DMAC as an example.

[dan.j.williams@intel.com: update for timberdale]
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Li Yang <leoli@freescale.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Magnus Damm <damm@opensource.se>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Joe Perches <joe@perches.com>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-26 16:44:01 -07:00
Linus Torvalds 9bb676966a Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (28 commits)
  ioat: cleanup ->timer_fn() and ->cleanup_fn() prototypes
  ioat3: interrupt coalescing
  ioat: close potential BUG_ON race in the descriptor cleanup path
  ioat2: kill pending flag
  ioat3: use ioat2_quiesce()
  ioat3: cleanup, don't enable DCA completion writes
  DMAENGINE: COH 901 318 lli sg offset fix
  DMAENGINE: COH 901 318 configure channel direction
  DMAENGINE: COH 901 318 remove irq counting
  DMAENGINE: COH 901 318 descriptor pool refactoring
  DMAENGINE: COH 901 318 cleanups
  dma: Add MPC512x DMA driver
  Debugging options for the DMA engine subsystem
  iop-adma: redundant/wrong tests in iop_*_count()?
  dmatest: fix handling of an even number of xor_sources
  dmatest: correct raid6 PQ test
  fsldma: Fix cookie issues
  fsldma: Fix cookie issues
  dma: cases IPU_PIX_FMT_BGRA32, BGR32 and ABGR32 are the same in ipu_ch_param_set_size()
  dma: make Open Firmware device id constant
  ...
2010-03-04 08:20:14 -08:00
Steven J. Magnani 76bd061f5c fsldma: Fix cookie issues
fsl_dma_update_completed_cookie() appears to calculate the last completed
cookie incorrectly in the corner case where DMA on cookie 1 is in progress
just following a cookie wrap.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Acked-by: Ira W. Snyder <iws@ovro.caltech.edu>
[dan.j.williams@intel.com: fix an integer overflow warning with INT_MAX]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-02-28 22:18:16 -07:00
Tejun Heo a29d8b8e2d percpu: add __percpu sparse annotations to what's left
Add __percpu sparse annotations to places which didn't make it in one
of the previous patches.  All converions are trivial.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors.  This patch doesn't affect normal builds.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Neil Brown <neilb@suse.de>
2010-02-17 11:17:38 +09:00
Guennadi Liakhovetski a88f666707 dmaengine: clarify the meaning of the DMA_CTRL_ACK flag
DMA_CTRL_ACK's description applies to its clear state, not to its set state.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-12-10 23:43:19 -07:00
Dan Williams bbb20089a3 Merge branch 'dmaengine' into async-tx-next
Conflicts:
	crypto/async_tx/async_xor.c
	drivers/dma/ioat/dma_v2.h
	drivers/dma/ioat/pci.c
	drivers/md/raid5.c
2009-09-08 17:55:21 -07:00
Dan Williams 0803172778 dmaengine: kill tx_list
The tx_list attribute of struct dma_async_tx_descriptor is common to
most, but not all dma driver implementations.  None of the upper level
code (dmaengine/async_tx) uses it, so allow drivers to implement it
locally if they need it.  This saves sizeof(struct list_head) bytes for
drivers that do not manage descriptors with a linked list (e.g.: ioatdma
v2,3).

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-08 17:53:04 -07:00
Dan Williams 83544ae9f3 dmaengine, async_tx: support alignment checks
Some engines have transfer size and address alignment restrictions.  Add
a per-operation alignment property to struct dma_device that the async
routines and dmatest can use to check alignment capabilities.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-08 17:42:53 -07:00
Dan Williams 9308add6ea dmaengine: cleanup unused transaction types
No drivers currently implement these operation types, so they can be
deleted.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-08 17:42:52 -07:00
Dan Williams 138f4c359d dmaengine, async_tx: add a "no channel switch" allocator
Channel switching is problematic for some dmaengine drivers as the
architecture precludes separating the ->prep from ->submit.  In these
cases the driver can select ASYNC_TX_DISABLE_CHANNEL_SWITCH to modify
the async_tx allocator to only return channels that support all of the
required asynchronous operations.

For example MD_RAID456=y selects support for asynchronous xor, xor
validate, pq, pq validate, and memcpy.  When
ASYNC_TX_DISABLE_CHANNEL_SWITCH=y any channel with all these
capabilities is marked DMA_ASYNC_TX allowing async_tx_find_channel() to
quickly locate compatible channels with the guarantee that dependency
chains will remain on one channel.  When
ASYNC_TX_DISABLE_CHANNEL_SWITCH=n async_tx_find_channel() may select
channels that lead to operation chains that need to cross channel
boundaries using the async_tx channel switch capability.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-08 17:42:51 -07:00
Dan Williams 0403e38277 dmaengine: add fence support
Some engines optimize operation by reading ahead in the descriptor chain
such that descriptor2 may start execution before descriptor1 completes.
If descriptor2 depends on the result from descriptor1 then a fence is
required (on descriptor2) to disable this optimization.  The async_tx
api could implicitly identify dependencies via the 'depend_tx'
parameter, but that would constrain cases where the dependency chain
only specifies a completion order rather than a data dependency.  So,
provide an ASYNC_TX_FENCE to explicitly identify data dependencies.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-08 17:42:50 -07:00
Dan Williams f9dd213437 Merge branch 'md-raid6-accel' into ioat3.2
Conflicts:
	include/linux/dmaengine.h
2009-09-08 17:42:29 -07:00
Dan Williams b2f46fd8ef async_tx: add support for asynchronous GF multiplication
[ 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: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Reviewed-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:09:27 -07:00
Dan Williams ad283ea4a3 async_tx: add sum check flags
Replace the flat zero_sum_result with a collection of flags to contain
the P (xor) zero-sum result, and the soon to be utilized Q (raid6 reed
solomon syndrome) zero-sum result.  Use the SUM_CHECK_ namespace instead
of DMA_ since these flags will be used on non-dma-zero-sum enabled
platforms.

Reviewed-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:09:26 -07:00
Maciej Sosnowski 4f005dbe55 ioatdma: fix "ioatdma frees DMA memory with wrong function"
as reported by Alexander Beregalov <a.beregalov@gmail.com>

ioatdma 0000:00:08.0: DMA-API: device driver frees DMA memory with
wrong function [device address=0x000000007f76f800] [size=2000 bytes]
[map
ped as single] [unmapped as page]

The ioatdma driver was unmapping all regions
(either allocated as page or single) using unmap_page.
This patch lets dma driver recognize if unmap_single or unmap_page should be used.
It introduces two new dma control flags:
DMA_COMPL_SRC_UNMAP_SINGLE and DMA_COMPL_DEST_UNMAP_SINGLE.
They should be set to indicate dma driver to do dma-unmapping as single
(first one for the source, tha latter for the destination).
If respective flag is not set, the driver assumes dma-unmapping as page.

Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Tested-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-05-12 14:41:47 -07:00
Dan Williams 099f53cb50 async_tx: rename zero_sum to val
'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: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-04-08 14:28:37 -07:00
Atsushi Nemoto 0f571515c3 dmaengine: Add privatecnt to revert DMA_PRIVATE property
Currently dma_request_channel() set DMA_PRIVATE capability but never
clear it.  So if a public channel was once grabbed by
dma_request_channel(), the device stay PRIVATE forever.  Add
privatecnt member to dma_device to correctly revert it.

[lg@denx.de: fix bad usage of 'chan' in dma_async_device_register]
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-26 09:48:09 -07:00
Dan Williams 729b5d1b8e dmaengine: allow dma support for async_tx to be toggled
Provide a config option for blocking the allocation of dma channels to
the async_tx api.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-25 09:13:25 -07:00
Dan Williams 54aee6a5f5 dmaengine: kill some unused headers
The dmaengine redux left some unneeded headers in
include/linux/dmaengine.h, clean them up.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-25 09:13:24 -07:00
Linus Torvalds 5dc18f51a2 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
  dmatest: fix use after free in dmatest_exit
  ipu_idmac: fix spinlock type
  iop-adma, mv_xor: fix mem leak on self-test setup failure
  fsldma: fix off by one in dma_halt
  I/OAT: fail self-test if callback test reaches timeout
  I/OAT: update driver version and copyright dates
  I/OAT: list usage cleanup
  I/OAT: set tcp_dma_copybreak to 256k for I/OAT ver.3
  I/OAT: cancel watchdog before dma remove
  I/OAT: fail initialization on zero channels detection
  I/OAT: do not set DCACTRL_CMPL_WRITE_ENABLE for I/OAT ver.3
  I/OAT: add verification for proper APICID_TAG_MAP setting by BIOS
  dmaengine: update kerneldoc
2009-03-08 10:23:05 -07:00
Dan Williams 287d859222 atmel-mci: fix initialization of dma slave data
The conversion of atmel-mci to dma_request_channel missed the
initialization of the channel dma_slave information.  The filter_fn passed
to dma_request_channel is responsible for initializing the channel's
private data.  This implementation has the additional benefit of enabling
a generic client-channel data passing mechanism.

Reviewed-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-18 15:37:55 -08:00
Johannes Weiner 1d93e52eb4 dmaengine: update kerneldoc
Some of the kerneldoc comments in the dmaengine header describe
already removed structure members.  Remove them.

Also add a short description for dma_device->device_is_tx_complete.

Signed-off-by: Johannes Weiner <jw@emlix.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-02-11 17:12:27 -07:00
David S. Miller b4bd07c20b net_dma: call dmaengine_get only if NET_DMA enabled
Based upon a patch from Atsushi Nemoto <anemo@mba.ocn.ne.jp>

--------------------
The commit 649274d993 ("net_dma:
acquire/release dma channels on ifup/ifdown") added unconditional call
of dmaengine_get() to net_dma.  The API should be called only if
NET_DMA was enabled.
--------------------

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Dan Williams <dan.j.williams@intel.com>
2009-02-06 22:06:43 -08:00
Linus Torvalds 7954d5cf39 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
  i.MX31: framebuffer driver
  i.MX31: Image Processing Unit DMA and IRQ drivers
  dmaengine: add async_tx_clear_ack() macro
  dmaengine: dma_issue_pending_all == nop when CONFIG_DMA_ENGINE=n
  dmaengine: kill some dubious WARN_ONCEs
  fsldma: print correct IRQ on mpc83xx
  fsldma: check for NO_IRQ in fsl_dma_chan_remove()
  dmatest: Use custom map/unmap for destination buffer
  fsldma: use a valid 'device' for dma_pool_create
  dmaengine: fix dependency chaining
2009-01-26 10:13:08 -08:00
Guennadi Liakhovetski ef560682a9 dmaengine: add async_tx_clear_ack() macro
To complete the DMA_CTRL_ACK handling API add a async_tx_clear_ack() macro.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-19 15:36:21 -07:00
Dan Williams c50331e8be dmaengine: dma_issue_pending_all == nop when CONFIG_DMA_ENGINE=n
The device list will always be empty in this configuration, so no need
to walk the list.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-19 15:35:54 -07:00
Dan Williams 649274d993 net_dma: acquire/release dma channels on ifup/ifdown
The recent dmaengine rework removed the capability to remove dma device
driver modules while net_dma is active.  Rather than notify
dmaengine-clients that channels are trying to be removed, we now rely on
clients to notify dmaengine when they no longer have a need for
channels.  Teach net_dma to release channels by taking dmaengine
references at netdevice open and dropping references at netdevice close.

Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-11 00:20:39 -08:00
Dan Williams 864498aaa9 dmaengine: use idr for registering dma device numbers
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>
2009-01-06 11:38:21 -07:00
Dan Williams 41d5e59c12 dmaengine: add a release for dma class devices and dependent infrastructure
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>
2009-01-06 11:38:21 -07:00
Dan Williams 7dd6025101 dmaengine: kill enum dma_state_client
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>
2009-01-06 11:38:19 -07:00
Dan Williams f27c580c36 dmaengine: remove 'bigref' infrastructure
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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06 11:38:18 -07:00
Dan Williams aa1e6f1a38 dmaengine: kill struct dma_client and supporting infrastructure
All users have been converted to either the general-purpose allocator,
dma_find_channel, or dma_request_channel.

Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06 11:38:17 -07:00
Dan Williams 209b84a88f dmaengine: replace dma_async_client_register with dmaengine_get
Now that clients no longer need to be notified of channel arrival
dma_async_client_register can simply increment the dmaengine_ref_count.

Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06 11:38:17 -07:00
Dan Williams 74465b4ff9 atmel-mci: convert to dma_request_channel and down-level dma_slave
dma_request_channel provides an exclusive channel, so we no longer need to
pass slave data through dmaengine.

Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06 11:38:16 -07:00
Dan Williams 33df8ca068 dmatest: convert to dma_request_channel
Replace the client registration infrastructure with a custom loop to
poll for channels.  Once dma_request_channel returns NULL stop asking
for channels.  A userspace side effect of this change if that loading
the dmatest module before loading a dma driver will result in no
channels being found, previously dmatest would get a callback.  To
facilitate testing in the built-in case dmatest_init is marked as a
late_initcall.  Another side effect is that channels under test can not
be used for any other purpose.

Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06 11:38:15 -07:00
Dan Williams 59b5ec2144 dmaengine: introduce dma_request_channel and private channels
This interface is primarily for device-to-memory clients which need to
search for dma channels with platform-specific characteristics.  The
prototype is:

struct dma_chan *dma_request_channel(dma_cap_mask_t mask,
                                     dma_filter_fn filter_fn,
                                     void *filter_param);

When the optional 'filter_fn' parameter is set to NULL
dma_request_channel simply returns the first channel that satisfies the
capability mask.  Otherwise, when the mask parameter is insufficient for
specifying the necessary channel, the filter_fn routine can be used to
disposition the available channels in the system. The filter_fn routine
is called once for each free channel in the system.  Upon seeing a
suitable channel filter_fn returns DMA_ACK which flags that channel to
be the return value from dma_request_channel.  A channel allocated via
this interface is exclusive to the caller, until dma_release_channel()
is called.

To ensure that all channels are not consumed by the general-purpose
allocator the DMA_PRIVATE capability is provided to exclude a dma_device
from general-purpose (memory-to-memory) consideration.

Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06 11:38:15 -07:00
Dan Williams 2ba05622b8 dmaengine: provide a common 'issue_pending_all' implementation
async_tx and net_dma each have open-coded versions of issue_pending_all,
so provide a common routine in dmaengine.

The implementation needs to walk the global device list, so implement
rcu to allow dma_issue_pending_all to run lockless.  Clients protect
themselves from channel removal events by holding a dmaengine reference.

Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06 11:38:14 -07:00
Dan Williams bec085134e dmaengine: centralize channel allocation, introduce dma_find_channel
Allowing multiple clients to each define their own channel allocation
scheme quickly leads to a pathological situation.  For memory-to-memory
offload all clients can share a central allocator.

This simply moves the existing async_tx allocator to dmaengine with
minimal fixups:
* async_tx.c:get_chan_ref_by_cap --> dmaengine.c:nth_chan
* async_tx.c:async_tx_rebalance --> dmaengine.c:dma_channel_rebalance
* split out common code from async_tx.c:__async_tx_find_channel -->
  dma_find_channel

Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06 11:38:14 -07:00
Dan Williams 6f49a57aa5 dmaengine: up-level reference counting to the module level
Simply, if a client wants any dmaengine channel then prevent all dmaengine
modules from being removed.  Once the clients are done re-enable module
removal.

Why?, beyond reducing complication:
1/ Tracking reference counts per-transaction in an efficient manner, as
   is currently done, requires a complicated scheme to avoid cache-line
   bouncing effects.
2/ Per-transaction ref-counting gives the false impression that a
   dma-driver can be gracefully removed ahead of its user (net, md, or
   dma-slave)
3/ None of the in-tree dma-drivers talk to hot pluggable hardware, but
   if such an engine were built one day we still would not need to notify
   clients of remove events.  The driver can simply return NULL to a
   ->prep() request, something that is much easier for a client to handle.

Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-06 11:38:14 -07:00
Dan Williams 07f2211e4f dmaengine: remove dependency on async_tx
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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-01-05 18:10:19 -07:00
Dan Williams 0839875e0c async_tx: make async_tx_test_ack a boolean routine
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-17 17:59:56 -07:00
Haavard Skinnemoen dc0ee6435c dmaengine: Add slave DMA interface
This patch adds the necessary interfaces to the DMA Engine framework
to use functionality found on most embedded DMA controllers: DMA from
and to I/O registers with hardware handshaking.

In this context, hardware hanshaking means that the peripheral that
owns the I/O registers in question is able to tell the DMA controller
when more data is available for reading, or when there is room for
more data to be written. This usually happens internally on the chip,
but these signals may also be exported outside the chip for things
like IDE DMA, etc.

A new struct dma_slave is introduced. This contains information that
the DMA engine driver needs to set up slave transfers to and from a
slave device. Most engines supporting DMA slave transfers will want to
extend this structure with controller-specific parameters.  This
additional information is usually passed from the platform/board code
through the client driver.

A "slave" pointer is added to the dma_client struct. This must point
to a valid dma_slave structure iff the DMA_SLAVE capability is
requested.  The DMA engine driver may use this information in its
device_alloc_chan_resources hook to configure the DMA controller for
slave transfers from and to the given slave device.

A new operation for preparing slave DMA transfers is added to struct
dma_device. This takes a scatterlist and returns a single descriptor
representing the whole transfer.

Another new operation for terminating all pending transfers is added as
well. The latter is needed because there may be errors outside the scope
of the DMA Engine framework that may require DMA operations to be
terminated prematurely.

DMA Engine drivers may extend the dma_device, dma_chan and/or
dma_slave_descriptor structures to allow controller-specific
operations. The client driver can detect such extensions by looking at
the DMA Engine's struct device, or it can request a specific DMA
Engine device by setting the dma_dev field in struct dma_slave.

dmaslave interface changes since v4:
  * Fix checkpatch errors
  * Fix changelog (there are no slave descriptors anymore)

dmaslave interface changes since v3:
  * Use dma_data_direction instead of a new enum
  * Submit slave transfers as scatterlists
  * Remove the DMA slave descriptor struct

dmaslave interface changes since v2:
  * Add a dma_dev field to struct dma_slave. If set, the client can
    only be bound to the DMA controller that corresponds to this
    device.  This allows controller-specific extensions of the
    dma_slave structure; if the device matches, the controller may
    safely assume its extensions are present.
  * Move reg_width into struct dma_slave as there are currently no
    users that need to be able to set the width on a per-transfer
    basis.

dmaslave interface changes since v1:
  * Drop the set_direction and set_width descriptor hooks. Pass the
    direction and width to the prep function instead.
  * Declare a dma_slave struct with fixed information about a slave,
    i.e. register addresses, handshake interfaces and such.
  * Add pointer to a dma_slave struct to dma_client. Can be NULL if
    the DMA_SLAVE capability isn't requested.
  * Drop the set_slave device hook since the alloc_chan_resources hook
    now has enough information to set up the channel for slave
    transfers.

Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-08 11:59:35 -07:00
Dan Williams e1d181efb1 dmaengine: add DMA_COMPL_SKIP_{SRC,DEST}_UNMAP flags to control dma unmap
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: Saeed Bishara <saeed@marvell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-08 11:59:12 -07:00
Haavard Skinnemoen 848c536a37 dmaengine: Add dma_client parameter to device_alloc_chan_resources
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: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-08 11:58:58 -07:00