linux-stable.git/drivers/dma/ioat, branch linux-3.12.y

ioat: fix tasklet tear down

2014-03-05T16:13:53+00:00

commit da87ca4d4ca101f177fffd84f1f0a5e4c0343557 upstream.

Since commit 77873803363c "net_dma: mark broken" we no longer pin dma
engines active for the network-receive-offload use case.  As a result
the ->free_chan_resources() that occurs after the driver self test no
longer has a NET_DMA induced ->alloc_chan_resources() to back it up.  A
late firing irq can lead to ksoftirqd spinning indefinitely due to the
tasklet_disable() performed by ->free_chan_resources().  Only
->alloc_chan_resources() can clear this condition in affected kernels.

This problem has been present since commit 3e037454bcfa "I/OAT: Add
support for MSI and MSI-X" in 2.6.24, but is now exposed. Given the
NET_DMA use case is deprecated we can revisit moving the driver to use
threaded irqs.  For now, just tear down the irq and tasklet properly by:

1/ Disable the irq from triggering the tasklet

2/ Disable the irq from re-arming

3/ Flush inflight interrupts

4/ Flush the timer

5/ Flush inflight tasklets

References:
https://lkml.org/lkml/2014/1/27/282
https://lkml.org/lkml/2014/2/19/672

Cc: Ingo Molnar 
Cc: Steven Rostedt 
Reported-by: Mike Galbraith 
Reported-by: Stanislav Fomichev 
Tested-by: Mike Galbraith 
Tested-by: Stanislav Fomichev 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Dan Williams 
Signed-off-by: Jiri Slaby

ioatdma: fix selection of 16 vs 8 source path

2013-12-04T19:05:37+00:00

commit 21e96c7313486390c694919522a76dfea0a86c59 upstream.

When performing continuations there are implied sources that need to be
added to the source count. Quoting dma_set_maxpq:

/* dma_maxpq - reduce maxpq in the face of continued operations
 * @dma - dma device with PQ capability
 * @flags - to check if DMA_PREP_CONTINUE and DMA_PREP_PQ_DISABLE_P are set
 *
 * 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)
 *
 * In the case where P is disabled we only need 1 extra source:
 * 1/ {01} * Q : use Q to continue Q' calculation
 */

...fix the selection of the 16 source path to take these implied sources
into account.

Note this also kills the BUG_ON(src_cnt < 9) check in
__ioat3_prep_pq16_lock().  Besides not accounting for implied sources
the check is redundant given we already made the path selection.

Cc: Dave Jiang 
Acked-by: Dave Jiang 
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

ioatdma: fix sed pool selection

2013-12-04T19:05:36+00:00

commit 5d48b9b5d80e3aa38a5161565398b1e48a650573 upstream.

The array to lookup the sed pool based on the number of sources
(pq16_idx_to_sedi) is 16 entries and expects a max source index.
However, we pass the total source count which runs off the end of the
array when src_cnt == 16.  The minimal fix is to just pass src_cnt-1,
but given we know the source count is > 8 we can just calculate the sed
pool by (src_cnt - 2) >> 3.

Cc: Dave Jiang 
Acked-by: Dave Jiang 
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

ioatdma: Fix bug in selftest after removal of DMA_MEMSET.

2013-12-04T19:05:36+00:00

commit ac7d631f7d9f9e4e6116c4a72b6308067d0a2226 upstream.

Commit 48a9db4 (3.11) removed the memset op in the xor selftest for ioatdma.
The issue is that with the removal of that op, it never replaced the memset
with a CPU memset. The memory being operated on is expected to be zeroes but
was not. This is causing the xor selftest to fail.

Signed-off-by: Dave Jiang 
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

ioatdma: silence GCC warnings

2013-08-23T07:21:44+00:00

Building dma_v3.o triggers a GCC warning:
    drivers/dma/ioat/dma_v3.c: In function ‘__ioat3_prep_pq16_lock’:
    drivers/dma/ioat/dma_v3.c:264:11: warning: array subscript is below array bounds [-Warray-bounds]
    drivers/dma/ioat/dma_v3.c:264:11: warning: array subscript is below array bounds [-Warray-bounds]

This warning is caused by pq16_set_src(). It uses "int idx" as an index
to an eight element array. Changing "idx" to "unsigned" silences this
warning. Apparently GCC can then determine that "idx" will never be
negative.

Signed-off-by: Paul Bolle 
Acked-by: Dave Jiang 
Signed-off-by: Dan Williams

ioatdma: disable RAID on non-Atom platforms and reenable unaligned copies

2013-08-23T05:57:39+00:00

Disable RAID on non-Atom platform and remove related fixups such as the
64-byte alignement restriction on legacy DMA operations (introduced in
commit f26df1a1 as a workaround for silicon errata).

Signed-off-by: Brice Goglin 
Acked-by: Dave Jiang 
Acked-by: Jon Mason 
Signed-off-by: Dan Williams

drivers/dma: remove unused support for MEMSET operations

2013-07-03T23:07:42+00:00

There have never been any real users of MEMSET operations since they
have been introduced in January 2007 by commit 7405f74badf4 ("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: Bartlomiej Zolnierkiewicz 
Signed-off-by: Kyungmin Park 
Signed-off-by: Sebastian Hesselbarth 
Cc: Vinod Koul 
Acked-by: Dan Williams 
Cc: Tomasz Figa 
Cc: Herbert Xu 
Cc: Olof Johansson 
Cc: Kevin Hilman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma

2013-05-09T16:46:45+00:00

Pull slave-dmaengine updates from Vinod Koul:
 "This time we have dmatest improvements from Andy along with dw_dmac
  fixes.  He has also done support for acpi for dmanegine.

  Also we have bunch of fixes going in DT support for dmanegine for
  various folks.  Then Haswell and other ioat changes from Dave and
  SUDMAC support from Shimoda."

* 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (53 commits)
  dma: tegra: implement suspend/resume callbacks
  dma:of: Use a mutex to protect the of_dma_list
  dma: of: Fix of_node reference leak
  dmaengine: sirf: move driver init from module_init to subsys_initcall
  sudmac: add support for SUDMAC
  dma: sh: add Kconfig
  at_hdmac: move to generic DMA binding
  ioatdma: ioat3_alloc_sed can be static
  ioatdma: Adding write back descriptor error status support for ioatdma 3.3
  ioatdma: S1200 platforms ioatdma channel 2 and 3 falsely advertise RAID cap
  ioatdma: Adding support for 16 src PQ ops and super extended descriptors
  ioatdma: Removing hw bug workaround for CB3.x .2 and earlier
  dw_dmac: add ACPI support
  dmaengine: call acpi_dma_request_slave_channel as well
  dma: acpi-dma: introduce ACPI DMA helpers
  dma: of: Remove unnecessary list_empty check
  DMA: OF: Check properties value before running be32_to_cpup() on it
  DMA: of: Constant names
  ioatdma: skip silicon bug workaround for pq_align for cb3.3
  ioatdma: Removing PQ val disable for cb3.3
  ...

ioatdma: ioat3_alloc_sed can be static

2013-04-16T13:19:40+00:00

Reported-by: Fengguang Wu 
Signed-off-by: Fengguang Wu 
Acked-by: Dave Jiang 
Signed-off-by: Vinod Koul

ioatdma: Adding write back descriptor error status support for ioatdma 3.3

2013-04-15T17:16:15+00:00

v3.3 provides support for write back descriptor error status. This allows
reporting of errors in a descriptor field. In supporting this, certain
errors such as P/Q validation errors no longer halts the channel. The DMA
engine can continue to execute until the end of the chain and allow software
to report the "errors" up the stack. We are also going to mask those error
interrupts and handle them when the "chain" has completed at the end.

Signed-off-by: Dave Jiang 
Acked-by: Dan Williams 
Signed-off-by: Vinod Koul