linux.git/drivers/dma/ioat, branch v3.17

ioat: fix tasklet tear down

2014-02-25T17:44:20+00:00

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 
Cc: 
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

drivers/dma/ioat/dma.c: check DMA mapping error in ioat_dma_self_test()

2014-01-02T22:40:30+00:00

Check DMA mapping return values in function ioat_dma_self_test() to get
rid of following warning message.

  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1203 at lib/dma-debug.c:937 check_unmap+0x4c0/0x9a0()
  ioatdma 0000:00:04.0: DMA-API: device driver failed to check map error[device address=0x000000085191b000] [size=2000 bytes] [mapped as single]
  Modules linked in: ioatdma(+) mac_hid wmi acpi_pad lp parport hidd_generic usbhid hid ixgbe isci dca libsas ahci ptp libahci scsi_transport_sas meegaraid_sas pps_core mdio
  CPU: 0 PID: 1203 Comm: systemd-udevd Not tainted 3.13.0-rc4+ #8
  Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS BRIVTIIN1.86B.0044.L09.1311181644 11/18/2013
  Call Trace:
    dump_stack+0x4d/0x66
    warn_slowpath_common+0x7d/0xa0
    warn_slowpath_fmt+0x4c/0x50
    check_unmap+0x4c0/0x9a0
    debug_dma_unmap_page+0x81/0x90
    ioat_dma_self_test+0x3d2/0x680 [ioatdma]
    ioat3_dma_self_test+0x12/0x30 [ioatdma]
    ioat_probe+0xf4/0x110 [ioatdma]
    ioat3_dma_probe+0x268/0x410 [ioatdma]
    ioat_pci_probe+0x122/0x1b0 [ioatdma]
    local_pci_probe+0x45/0xa0
    pci_device_probe+0xd9/0x130
    driver_probe_device+0x171/0x490
    __driver_attach+0x93/0xa0
    bus_for_each_dev+0x6b/0xb0
    driver_attach+0x1e/0x20
    bus_add_driver+0x1f8/0x2b0
    driver_register+0x81/0x110
    __pci_register_driver+0x60/0x70
    ioat_init_module+0x89/0x1000 [ioatdma]
    do_one_initcall+0xe2/0x250
    load_module+0x2313/0x2a00
    SyS_init_module+0xd9/0x130
    system_call_fastpath+0x1a/0x1f
  ---[ end trace 990c591681d27c31 ]---
  Mapped at:
    debug_dma_map_page+0xbe/0x180
    ioat_dma_self_test+0x1ab/0x680 [ioatdma]
    ioat3_dma_self_test+0x12/0x30 [ioatdma]
    ioat_probe+0xf4/0x110 [ioatdma]
    ioat3_dma_probe+0x268/0x410 [ioatdma]

Signed-off-by: Jiang Liu 
Cc: Vinod Koul 
Cc: Dan Williams 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Kyungmin Park 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge commit 'dmaengine-3.13-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine

2013-11-16T06:32:36+00:00

Pull dmaengine changes from Dan

1/ Bartlomiej and Dan finalized a rework of the dma address unmap
   implementation.

2/ In the course of testing 1/ a collection of enhancements to dmatest
   fell out.  Notably basic performance statistics, and fixed / enhanced
   test control through new module parameters 'run', 'wait', 'noverify',
   and 'verbose'.  Thanks to Andriy and Linus for their review.

3/ Testing the raid related corner cases of 1/ triggered bugs in the
   recently added 16-source operation support in the ioatdma driver.

4/ Some minor fixes / cleanups to mv_xor and ioatdma.

Conflicts:
	drivers/dma/dmatest.c

Signed-off-by: Vinod Koul

ioat: fix ioat3_irq_reinit

2013-11-14T19:04:42+00:00

The implementation of ioat3_irq_reinit has two bugs:

1/ The mode is incorrectly set to MSIX for the MSI case

2/ The 'dev_id' parameter to free_irq is the ioatdma_device not the channel in
   the msi and intx case

Include a small cleanup to clarify that ioat3_irq_reinit is only for bwd
hardware

Cc: Dave Jiang 
Signed-off-by: Dan Williams

ioat: kill msix_single_vector support

2013-11-14T19:04:42+00:00

Once we have determined that we will not have all of our desired msix
vectors there is no point in attempting a single msix allocation.  The
driver will already need to read registers to determine the source of
the interrupt the fact that it is msix is moot.  Fallback directly to
msi.

Reported-by: Alexander Gordeev 
Cc: Dave Jiang 
Signed-off-by: Dan Williams

ioatdma: clean up sed pool kmem_cache

2013-11-14T19:04:41+00:00

Use a single cache for all sed allocations.  No need to make it per
channel.  This also avoids the slub_debug warnings for multiple caches
with the same name.

Switching to dmam_pool_create() to fix leaking the dma pools on
initialization failure and lets us kill ioat3_dma_remove().

Cc: Dave Jiang 
Acked-by: Dave Jiang 
Signed-off-by: Dan Williams

ioatdma: fix selection of 16 vs 8 source path

2013-11-14T19:04:41+00:00

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: 
Cc: Dave Jiang 
Acked-by: Dave Jiang 
Signed-off-by: Dan Williams

ioatdma: fix sed pool selection

2013-11-14T19:04:41+00:00

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 
Cc: 
Acked-by: Dave Jiang 
Signed-off-by: Dan Williams

ioatdma: Fix bug in selftest after removal of DMA_MEMSET.

2013-11-14T19:04:41+00:00

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.

Cc: 
Signed-off-by: Dave Jiang 
Signed-off-by: Dan Williams

dmaengine: remove DMA unmap flags

2013-11-14T19:04:38+00:00

Remove no longer needed DMA unmap flags:
- DMA_COMPL_SKIP_SRC_UNMAP
- DMA_COMPL_SKIP_DEST_UNMAP
- DMA_COMPL_SRC_UNMAP_SINGLE
- DMA_COMPL_DEST_UNMAP_SINGLE

Cc: Vinod Koul 
Cc: Tomasz Figa 
Cc: Dave Jiang 
Signed-off-by: Bartlomiej Zolnierkiewicz 
Signed-off-by: Kyungmin Park 
Acked-by: Jon Mason 
Acked-by: Mark Brown 
[djbw: clean up straggling skip unmap flags in ntb]
Signed-off-by: Dan Williams