linux-toradex.git/include/linux/nvme.h, branch v4.11-rc3

nvme: Enable autonomous power state transitions

2017-02-22T20:34:00+00:00

NVMe devices can advertise multiple power states.  These states can
be either "operational" (the device is fully functional but possibly
slow) or "non-operational" (the device is asleep until woken up).
Some devices can automatically enter a non-operational state when
idle for a specified amount of time and then automatically wake back
up when needed.

The hardware configuration is a table.  For each state, an entry in
the table indicates the next deeper non-operational state, if any,
to autonomously transition to and the idle time required before
transitioning.

This patch teaches the driver to program APST so that each successive
non-operational state will be entered after an idle time equal to 100%
of the total latency (entry plus exit) associated with that state.
The maximum acceptable latency is controlled using dev_pm_qos
(e.g. power/pm_qos_latency_tolerance_us in sysfs); non-operational
states with total latency greater than this value will not be used.
As a special case, setting the latency tolerance to 0 will disable
APST entirely.  On hardware without APST support, the sysfs file will
not be exposed.

The latency tolerance for newly-probed devices is set by the module
parameter nvme_core.default_ps_max_latency_us.

In theory, the device can expose "default" APST table, but this
doesn't seem to function correctly on my device (Samsung 950), nor
does it seem particularly useful.  There is also an optional
mechanism by which a configuration can be "saved" so it will be
automatically loaded on reset.  This can be configured from
userspace, but it doesn't seem useful to support in the driver.

On my laptop, enabling APST seems to save nearly 1W.

The hardware tables can be decoded in userspace with nvme-cli.
'nvme id-ctrl /dev/nvmeN' will show the power state table and
'nvme get-feature -f 0x0c -H /dev/nvme0' will show the current APST
configuration.

This feature is quirked off on a known-buggy Samsung device.

Signed-off-by: Andy Lutomirski 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

nvme: Use CNS as 8-bit field and avoid endianness conversion

2017-02-22T20:34:00+00:00

This patch defines CNS field as 8-bit field and avoids cpu_to/from_le
conversions.
Also initialize nvme_command cns value explicitly to NVME_ID_CNS_NS
for readability (don't rely on the fact that NVME_ID_CNS_NS = 0).

Reviewed-by: Max Gurtovoy 
Signed-off-by: Parav Pandit 
Reviewed-by: Keith Busch 
Signed-off-by: Sagi Grimberg 
Signed-off-by: Jens Axboe

Merge branch 'for-4.11/next' into for-4.11/linus-merge

2017-02-17T21:08:19+00:00

Signed-off-by: Jens Axboe

nvme: Check for Security send/recv support before issuing commands.

2017-02-17T19:41:49+00:00

We need to verify that the controller supports the security
commands before actually trying to issue them.

Signed-off-by: Scott Bauer 
[hch: moved the check so that we don't call into the OPAL code if not
      supported]
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

nvme: support ranged discard requests

2017-02-08T20:43:10+00:00

NVMe supports up to 256 ranges per DSM command, so wire up support
for ranged discards up to that limit.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block

2016-12-13T18:19:16+00:00

Pull block layer updates from Jens Axboe:
 "This is the main block pull request this series. Contrary to previous
  release, I've kept the core and driver changes in the same branch. We
  always ended up having dependencies between the two for obvious
  reasons, so makes more sense to keep them together. That said, I'll
  probably try and keep more topical branches going forward, especially
  for cycles that end up being as busy as this one.

  The major parts of this pull request is:

   - Improved support for O_DIRECT on block devices, with a small
     private implementation instead of using the pig that is
     fs/direct-io.c. From Christoph.

   - Request completion tracking in a scalable fashion. This is utilized
     by two components in this pull, the new hybrid polling and the
     writeback queue throttling code.

   - Improved support for polling with O_DIRECT, adding a hybrid mode
     that combines pure polling with an initial sleep. From me.

   - Support for automatic throttling of writeback queues on the block
     side. This uses feedback from the device completion latencies to
     scale the queue on the block side up or down. From me.

   - Support from SMR drives in the block layer and for SD. From Hannes
     and Shaun.

   - Multi-connection support for nbd. From Josef.

   - Cleanup of request and bio flags, so we have a clear split between
     which are bio (or rq) private, and which ones are shared. From
     Christoph.

   - A set of patches from Bart, that improve how we handle queue
     stopping and starting in blk-mq.

   - Support for WRITE_ZEROES from Chaitanya.

   - Lightnvm updates from Javier/Matias.

   - Supoort for FC for the nvme-over-fabrics code. From James Smart.

   - A bunch of fixes from a whole slew of people, too many to name
     here"

* 'for-4.10/block' of git://git.kernel.dk/linux-block: (182 commits)
  blk-stat: fix a few cases of missing batch flushing
  blk-flush: run the queue when inserting blk-mq flush
  elevator: make the rqhash helpers exported
  blk-mq: abstract out blk_mq_dispatch_rq_list() helper
  blk-mq: add blk_mq_start_stopped_hw_queue()
  block: improve handling of the magic discard payload
  blk-wbt: don't throttle discard or write zeroes
  nbd: use dev_err_ratelimited in io path
  nbd: reset the setup task for NBD_CLEAR_SOCK
  nvme-fabrics: Add FC LLDD loopback driver to test FC-NVME
  nvme-fabrics: Add target support for FC transport
  nvme-fabrics: Add host support for FC transport
  nvme-fabrics: Add FC transport LLDD api definitions
  nvme-fabrics: Add FC transport FC-NVME definitions
  nvme-fabrics: Add FC transport error codes to nvme.h
  Add type 0x28 NVME type code to scsi fc headers
  nvme-fabrics: patch target code in prep for FC transport support
  nvme-fabrics: set sqe.command_id in core not transports
  parser: add u64 number parser
  nvme-rdma: align to generic ib_event logging helper
  ...

nvme-fabrics: Add FC transport error codes to nvme.h

2016-12-06T08:17:56+00:00

Signed-off-by: James Smart 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Jay Freyensee 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Christoph Hellwig

nvme.h: add Write Zeroes definitions

2016-12-01T14:58:40+00:00

Add the command structure, optional command set support (ONCS) bit and
a new error code for the Write Zeroes command.

Signed-off-by: Chaitanya Kulkarni 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

nvme: introduce struct nvme_request

2016-11-10T17:06:24+00:00

This adds a shared per-request structure for all NVMe I/O.  This structure
is embedded as the first member in all NVMe transport drivers request
private data and allows to implement common functionality between the
drivers.

The first use is to replace the current abuse of the SCSI command
passthrough fields in struct request for the NVMe command passthrough,
but it will grow a field more fields to allow implementing things
like common abort handlers in the future.

The passthrough commands are handled by having a pointer to the SQE
(struct nvme_command) in struct nvme_request, and the union of the
possible result fields, which had to be turned from an anonymous
into a named union for that purpose.  This avoids having to pass
a reference to a full CQE around and thus makes checking the result
a lot more lightweight.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Keith Busch 
Signed-off-by: Jens Axboe

nvme.h: add an enum for cns values

2016-10-19T17:36:22+00:00

Ported over from nvme-cli.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Gabriel Krisman Bertazi 
Reviewed-by: Keith Busch 
Signed-off-by: Jens Axboe