01 Nov, 2011

1 commit


22 Jun, 2011

1 commit

  • Remove linux/mm.h inclusion from netdevice.h -- it's unused (I've checked manually).

    To prevent mm.h inclusion via other channels also extract "enum dma_data_direction"
    definition into separate header. This tiny piece is what gluing netdevice.h with mm.h
    via "netdevice.h => dmaengine.h => dma-mapping.h => scatterlist.h => mm.h".
    Removal of mm.h from scatterlist.h was tried and was found not feasible
    on most archs, so the link was cutoff earlier.

    Hope people are OK with tiny include file.

    Note, that mm_types.h is still dragged in, but it is a separate story.

    Signed-off-by: Alexey Dobriyan
    Signed-off-by: David S. Miller

    Alexey Dobriyan
     

31 Mar, 2011

1 commit


28 Oct, 2010

1 commit

  • * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (48 commits)
    DMAENGINE: move COH901318 to arch_initcall
    dma: imx-dma: fix signedness bug
    dma/timberdale: simplify conditional
    ste_dma40: remove channel_type
    ste_dma40: remove enum for endianess
    ste_dma40: remove TIM_FOR_LINK option
    ste_dma40: move mode_opt to separate config
    ste_dma40: move channel mode to a separate field
    ste_dma40: move priority to separate field
    ste_dma40: add variable to indicate valid dma_cfg
    async_tx: make async_tx channel switching opt-in
    move async raid6 test to lib/Kconfig.debug
    dmaengine: Add Freescale i.MX1/21/27 DMA driver
    intel_mid_dma: change the slave interface
    intel_mid_dma: fix the WARN_ONs
    intel_mid_dma: Add sg list support to DMA driver
    intel_mid_dma: Allow DMAC2 to share interrupt
    intel_mid_dma: Allow IRQ sharing
    intel_mid_dma: Add runtime PM support
    DMAENGINE: define a dummy filter function for ste_dma40
    ...

    Linus Torvalds
     

27 Oct, 2010

1 commit

  • Ensure kmap_atomic() usage is strictly nested

    Signed-off-by: Peter Zijlstra
    Reviewed-by: Rik van Riel
    Acked-by: Chris Metcalf
    Cc: David Howells
    Cc: Hugh Dickins
    Cc: Ingo Molnar
    Cc: Thomas Gleixner
    Cc: "H. Peter Anvin"
    Cc: Steven Rostedt
    Cc: Russell King
    Cc: Ralf Baechle
    Cc: David Miller
    Cc: Paul Mackerras
    Cc: Benjamin Herrenschmidt
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Peter Zijlstra
     

08 Oct, 2010

1 commit

  • The prompt for "Self test for hardware accelerated raid6 recovery" does not
    belong in the top level configuration menu. All the options in
    crypto/async_tx/Kconfig are selected and do not depend on CRYPTO.
    Kconfig.debug seems like a reasonable fit.

    Cc: Herbert Xu
    Cc: David Woodhouse
    Signed-off-by: Dan Williams

    Dan Williams
     

09 Aug, 2010

1 commit


22 May, 2010

1 commit

  • * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
    DMAENGINE: extend the control command to include an arg
    async_tx: trim dma_async_tx_descriptor in 'no channel switch' case
    DMAENGINE: DMA40 fix for allocation of logical channel 0
    DMAENGINE: DMA40 support paused channel status
    dmaengine: mpc512x: Use resource_size
    DMA ENGINE: Do not reset 'private' of channel
    ioat: Remove duplicated devm_kzalloc() calls for ioatdma_device
    ioat3: disable cacheline-unaligned transfers for raid operations
    ioat2,3: convert to producer/consumer locking
    ioat: convert to circ_buf
    DMAENGINE: Support for ST-Ericssons DMA40 block v3
    async_tx: use of kzalloc/kfree requires the include of slab.h
    dmaengine: provide helper for setting txstate
    DMAENGINE: generic channel status v2
    DMAENGINE: generic slave control v2
    dma: timb-dma: Update comment and fix compiler warning
    dma: Add timb-dma
    DMAENGINE: COH 901 318 fix bytesleft
    DMAENGINE: COH 901 318 rename confusing vars

    Linus Torvalds
     

18 May, 2010

1 commit


05 May, 2010

1 commit

  • The raid6 recovery code should immediately drop back to the optimized
    synchronous path when a p+q dma resource is not available. Otherwise we
    run the non-optimized/multi-pass async code in sync mode.

    Verified with raid6test (NDISKS=255)

    Applies to kernels >= 2.6.32.

    Cc:
    Acked-by: NeilBrown
    Reported-by: H. Peter Anvin
    Signed-off-by: Dan Williams
    Signed-off-by: Linus Torvalds

    Dan Williams
     

30 Mar, 2010

1 commit

  • …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

18 Dec, 2009

1 commit


20 Nov, 2009

1 commit

  • ioat3.2 does not support asynchronous error notifications which makes
    the driver experience latencies when non-zero pq validate results are
    expected. Provide a mechanism for turning off async_xor_val and
    async_syndrome_val via Kconfig. This approach is generally useful for
    any driver that specifies ASYNC_TX_DISABLE_CHANNEL_SWITCH and would like
    to force the async_tx api to fall back to the synchronous path for
    certain operations.

    Signed-off-by: Dan Williams

    Dan Williams
     

30 Oct, 2009

1 commit


20 Oct, 2009

3 commits

  • The raid6 recovery code currently requires special handling of the
    4-disk and 5-disk recovery scenarios for the native layout. Quoting
    from commit 0a82a623:

    In these situations the default N-disk algorithm will present
    0-source or 1-source operations to dma devices. To cover for
    dma devices where the minimum source count is 2 we implement
    4-disk and 5-disk handling in the recovery code.

    The ddf layout presents disks=6 and disks=7 to the recovery code in
    these situations. Instead of looking at the number of disks count the
    number of non-zero sources in the list and call the special case code
    when the number of non-failed sources is 0 or 1.

    [neilb@suse.de: replace 'ddf' flag with counting good sources]
    Signed-off-by: Dan Williams

    Dan Williams
     
  • The global scribble page is used as a temporary destination buffer when
    disabling the P or Q result is requested. The local scribble buffer
    contains memory for performing address conversions. Rename the global
    variable to avoid confusion.

    Signed-off-by: Dan Williams

    Dan Williams
     
  • - update the kernel doc for async_syndrome to indicate what NULL in the
    source list means
    - whitespace fixups

    Signed-off-by: Dan Williams

    Dan Williams
     

16 Oct, 2009

2 commits

  • async_syndrome_val check the P and Q blocks used for RAID6
    calculations.
    With DDF raid6, some of the data blocks might be NULL, so
    this needs to be handled in the same way that async_gen_syndrome
    handles it.

    As async_syndrome_val calls async_xor, also enhance async_xor
    to detect and skip NULL blocks in the list.

    Signed-off-by: NeilBrown

    NeilBrown
     
  • md/raid6 passes a list of 'struct page *' to the async_tx routines,
    which then either DMA map them for offload, or take the page_address
    for CPU based calculations.

    For RAID6 we sometime leave 'blanks' in the list of pages.
    For CPU based calcs, we want to treat theses as a page of zeros.
    For offloaded calculations, we simply don't pass a page to the
    hardware.

    Currently the 'blanks' are encoded as a pointer to
    raid6_empty_zero_page. This is a 4096 byte memory region, not a
    'struct page'. This is mostly handled correctly but is rather ugly.

    So change the code to pass and expect a NULL pointer for the blanks.
    When taking page_address of a page, we need to check for a NULL and
    in that case use raid6_empty_zero_page.

    Signed-off-by: NeilBrown

    NeilBrown
     

22 Sep, 2009

1 commit


17 Sep, 2009

1 commit

  • Testing on x86_64 with NDISKS=255 yields:

    do_IRQ: modprobe near stack overflow (cur:ffff88007d19c000,sp:ffff88007d19c128)

    ...and eventually

    general protection fault: 0000 [#1]

    Moving the scribble buffers off the stack allows the test to complete
    successfully.

    Signed-off-by: Dan Williams

    Dan Williams
     

09 Sep, 2009

3 commits

  • 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 Williams
     
  • 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 Williams
     
  • 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 Williams
     

30 Aug, 2009

6 commits

  • Port drivers/md/raid6test/test.c to use the async raid6 recovery
    routines. This is meant as a unit test for raid6 acceleration drivers. In
    addition to the 16-drive test case this implements tests for the 4-disk and
    5-disk special cases (dma devices can not generically handle less than 2
    sources), and adds a test for the D+Q case.

    Reviewed-by: Andre Noll
    Acked-by: Maciej Sosnowski
    Signed-off-by: Dan Williams

    Dan Williams
     
  • async_raid6_2data_recov() recovers two data disk failures

    async_raid6_datap_recov() recovers a data disk and the P disk

    These routines are a port of the synchronous versions found in
    drivers/md/raid6recov.c. The primary difference is breaking out the xor
    operations into separate calls to async_xor. Two helper routines are
    introduced to perform scalar multiplication where needed.
    async_sum_product() multiplies two sources by scalar coefficients and
    then sums (xor) the result. async_mult() simply multiplies a single
    source by a scalar.

    This implemention also includes, in contrast to the original
    synchronous-only code, special case handling for the 4-disk and 5-disk
    array cases. In these situations the default N-disk algorithm will
    present 0-source or 1-source operations to dma devices. To cover for
    dma devices where the minimum source count is 2 we implement 4-disk and
    5-disk handling in the recovery code.

    [ Impact: asynchronous raid6 recovery routines for 2data and datap cases ]

    Cc: Yuri Tikhonov
    Cc: Ilya Yanok
    Cc: H. Peter Anvin
    Cc: David Woodhouse
    Reviewed-by: Andre Noll
    Acked-by: Maciej Sosnowski
    Signed-off-by: Dan Williams

    Dan Williams
     
  • [ 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
    Cc: David Woodhouse
    Signed-off-by: Yuri Tikhonov
    Signed-off-by: Ilya Yanok
    Reviewed-by: Andre Noll
    Acked-by: Maciej Sosnowski
    Signed-off-by: Dan Williams

    Dan Williams
     
  • We currently walk the parent chain when waiting for a given tx to
    complete however this walk may race with the driver cleanup routine.
    The routines in async_raid6_recov.c may fall back to the synchronous
    path at any point so we need to be prepared to call async_tx_quiesce()
    (which calls dma_wait_for_async_tx). To remove the ->parent walk we
    guarantee that every time a dependency is attached ->issue_pending() is
    invoked, then we can simply poll the initial descriptor until
    completion.

    This also allows for a lighter weight 'issue pending' implementation as
    there is no longer a requirement to iterate through all the channels'
    ->issue_pending() routines as long as operations have been submitted in
    an ordered chain. async_tx_issue_pending() is added for this case.

    Signed-off-by: Dan Williams

    Dan Williams
     
  • If module_init and module_exit are nops then neither need to be defined.

    [ Impact: pure cleanup ]

    Reviewed-by: Andre Noll
    Acked-by: Maciej Sosnowski
    Signed-off-by: Dan Williams

    Dan Williams
     
  • 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
    Acked-by: Maciej Sosnowski
    Signed-off-by: Dan Williams

    Dan Williams
     

04 Jun, 2009

3 commits

  • async_xor() needs space to perform dma and page address conversions. In
    most cases the code can simply reuse the struct page * array because the
    size of the native pointer matches the size of a dma/page address. In
    order to support archs where sizeof(dma_addr_t) is larger than
    sizeof(struct page *), or to preserve the input parameters, we utilize a
    memory region passed in by the caller.

    Since the code is now prepared to handle the case where it cannot
    perform address conversions on the stack, we no longer need the
    !HIGHMEM64G dependency in drivers/dma/Kconfig.

    [ Impact: don't clobber input buffers for address conversions ]

    Reviewed-by: Andre Noll
    Acked-by: Maciej Sosnowski
    Signed-off-by: Dan Williams

    Dan Williams
     
  • Prepare the api for the arrival of a new parameter, 'scribble'. This
    will allow callers to identify scratchpad memory for dma address or page
    address conversions. As this adds yet another parameter, take this
    opportunity to convert the common submission parameters (flags,
    dependency, callback, and callback argument) into an object that is
    passed by reference.

    Also, take this opportunity to fix up the kerneldoc and add notes about
    the relevant ASYNC_TX_* flags for each routine.

    [ Impact: moves api pass-by-value parameters to a pass-by-reference struct ]

    Signed-off-by: Andre Noll
    Acked-by: Maciej Sosnowski
    Signed-off-by: Dan Williams

    Dan Williams
     
  • In support of inter-channel chaining async_tx utilizes an ack flag to
    gate whether a dependent operation can be chained to another. While the
    flag is not set the chain can be considered open for appending. Setting
    the ack flag closes the chain and flags the descriptor for garbage
    collection. The ASYNC_TX_DEP_ACK flag essentially means "close the
    chain after adding this dependency". Since each operation can only have
    one child the api now implicitly sets the ack flag at dependency
    submission time. This removes an unnecessary management burden from
    clients of the api.

    [ Impact: clean up and enforce one dependency per operation ]

    Reviewed-by: Andre Noll
    Acked-by: Maciej Sosnowski
    Signed-off-by: Dan Williams

    Dan Williams
     

09 Apr, 2009

1 commit

  • '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
    Acked-by: Maciej Sosnowski
    Signed-off-by: Dan Williams

    Dan Williams
     

26 Mar, 2009

2 commits


07 Jan, 2009

4 commits

  • 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
    Signed-off-by: Dan Williams

    Dan Williams
     
  • 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
    Signed-off-by: Dan Williams

    Dan Williams
     
  • 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
    Signed-off-by: Dan Williams

    Dan Williams
     
  • 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
    Acked-by: Maciej Sosnowski
    Signed-off-by: Dan Williams

    Dan Williams