IOATDMA 3.4 supports PCIe LTR mechanism. The registers are non-standard
PCIe LTR support. This needs to be setup in order to not suffer performance
impact and provide proper power management. The channel is set to active
when it is allocated, and to passive when it's freed.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Adding support for new feature on ioatdma 3.4 hardware that provides
descriptor pre-fetching in order to reduce small DMA latencies.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
In preparation for removing the idle_notifier, remove its only user, the
i7300_idle driver.
i7300_idle was deployed in 2008 to reduce idle memory power on systems
using the i7300 chipset. The driver worked by throttling the
fully-buffered DIMMs during idle periods using the IOAT DMA engine.
The driver ran only on the i7300 chip-set, and no other hardware has used
this mechanism. The driver no longer has a maintainer.
Removing this driver will increase idle power on i7300 systems when they
run the new kernel without the driver.
Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/ad6a044e57cc75f44cc8621abe846e58f7882243.1479449716.git.len.brown@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Adding error handling to the ioatdma driver so that when a
read/write error occurs the error results are reported back and
all the remaining descriptors are aborted. This utilizes the new
dmaengine callback function that allows reporting of results.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
ioatdma by default is in snoop mode. Relaxed ordering according to spec
does not do anything in snoop mode. However, it causes hang or significant
performance degrade when tested with NTB. Disabling in the driver due to
some BIOS do not configure it correctly.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Remove pre-3.0 channel status reads. 3.0 and later chansts register
is 64bit and can be read 64bit. This was clarified with the hardware
architects and since the driver now only support 3.0+ we don't need the
legacy support
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Free Software Foundation mailing address has been moved in the past and some
of the addresses here are outdated. Remove them from file headers since the
COPYING file in the kernel sources includes it.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
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 <dave.jiang@intel.com>
Acked-by: Dan Williams <djbw@fb.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
v3.3 introduced 16 sources PQ operations. This also introduced super extended
descriptors to support the 16 srcs operations. This patch adds support for
the 16 sources ops and in turn adds the super extended descriptors for those
ops.
5 SED pools are created depending on the descriptor sizes. An SED can be a 64
bytes sized descriptor or larger and must be physically contiguous. A kmem
cache pool is created for allocating the software descriptor that manages the
hardware descriptor. The super extended descriptor will take place of extended
descriptor under certain operations and be "attached" to the op descriptor
during operation. This is a new feature for ioatdma v3.3.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <djbw@fb.com>
Acked-by: Dan Williams <djbw@fb.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
The PQ Val ops work on the newer hardware so we should actually provide support
for it and remove the disabling bits.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <djbw@fb.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
The hardware automatically disables further interrupts after each event
until rearmed. This allows a delay to be injected between the occurence
of the interrupt and the running of the cleanup routine. The delay is
scaled by the descriptor backlog and then written to the INTRDELAY
register which specifies the number of microseconds to hold off
interrupt delivery after an interrupt event occurs. According to
powertop this reduces the interrupt rate from ~5000 intr/s to ~150
intr/s per without affecting throughput (simple dd to a raid6 array).
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Put the ioat2 and ioat3 state machines in the halted state with all
errors cleared.
The ioat1 init path is not disturbed for stability, there are no
reported ioat1 initiaization issues.
Cc: <stable@kernel.org>
Reported-by: Roland Dreier <rdreier@cisco.com>
Tested-by: Roland Dreier <rdreier@cisco.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Error interrupts and error completions may cause channel hangs, so
poll the channel status register after a timeout.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
ioat3.2 adds xor offload support for up to 8 sources. It can also
perform an xor-zero-sum operation to validate whether all given sources
sum to zero, without writing to a destination. Xor descriptors differ
from memcpy in that one operation may require multiple descriptors
depending on the number of sources. When the number of sources exceeds
5 an extended descriptor is needed. These descriptors need to be
accounted for when updating the DMA_COUNT register.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Tag completion writes for direct cache access to reduce the latency of
checking for descriptor completions.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
ioat3.2 adds raid5 and raid6 offload capabilities.
Signed-off-by: Tom Picard <tom.s.picard@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
In order to support dynamic resizing of the descriptor ring or polling
for a descriptor in the presence of a hung channel the reset handler
needs to make progress while in a non-preemptible context. The current
workqueue implementation precludes polling channel reset completion
under spin_lock().
This conversion also allows us to return to opportunistic cleanup in the
ioat2 case as the timer implementation guarantees at least one cleanup
after every descriptor is submitted. This means the worst case
completion latency becomes the timer frequency (for exceptional
circumstances), but with the benefit of avoiding busy waiting when the
lock is contended.
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The register write in ioat_dma_cleanup_tasklet is unfortunate in two
ways:
1/ It clears the extra 'enable' bits that we set at alloc_chan_resources time
2/ It gives the impression that it disables interrupts when it is in
fact re-arming interrupts
[ Impact: fix, persist the value of the chanctrl register when re-arming ]
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The cleanup path makes an effort to only perform an atomic read of the
64-bit completion address. However in the 32-bit case it does not
matter if we read the upper-32 and lower-32 non-atomically because the
upper-32 will always be zero.
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
When first created the ioat driver was the only inhabitant of
drivers/dma/. Now, it is the only multi-file (more than a .c and a .h)
driver in the directory. Moving it to an ioat/ subdirectory allows the
naming convention to be cleaned up, and allows for future splitting of
the source files by hardware version (v1, v2, and v3).
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Dave Jiang