The current IPMI KCS code is waiting 100us for all transitions (roughly
between each byte either sent or received). However, most transitions
actually complete in 2-3 microseconds.

By polling the st

The current IPMI KCS code is waiting 100us for all transitions (roughly
between each byte either sent or received). However, most transitions
actually complete in 2-3 microseconds.

By polling the status register with a delay of 4us with exponential
backoff, the performance of most IPMI operations is significantly
improved:
- A BMC update on a Supermicro x9 or x11 motherboard goes from ~1 hour
to ~6-8 minutes.
- An ipmitool sensor list time improves by a factor of 4.

Testing showed no significant improvements on a modern server by using
a lower delay.

The changes should also generally reduce the total amount of CPU or
I/O bandwidth used for a given IPMI operation.

Submitted by: Loic Prylli <[email protected]>
Reviewed by: jhb
MFC after: 2 weeks
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D20527

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In cases where an application issues certain IPMI commands at a high
enough rate, the IPMI code can print large numbers of messages to the
console, such as:
ipmi0: KCS: Failed to read completion co

In cases where an application issues certain IPMI commands at a high
enough rate, the IPMI code can print large numbers of messages to the
console, such as:
ipmi0: KCS: Failed to read completion code
ipmi0: KCS error: ff
ipmi0: KCS: Failed to read completion code
ipmi0: KCS error: ff

These seem to be innocuous from a system standpoint, and the user-
space code can deal with the failures. Therefore, suppress printing
these messages to the console unless bootverbose is enabled.

Obtained from: Netflix, Inc.

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sys/dev: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error

sys/dev: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

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Watchdog drivers need to support rearming the watchdog in contexts which
are not permitted to sleep. Only use the IPMI watchdog with backends
which poll driver-initiated requests to meet this requir

Watchdog drivers need to support rearming the watchdog in contexts which
are not permitted to sleep. Only use the IPMI watchdog with backends
which poll driver-initiated requests to meet this requirement.

In practice this means that watchdogs will no longer be used on systems
that use the SSIF backend.

Differential Revision: https://reviews.freebsd.org/D2062
MFC after: 2 weeks

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Use direct hardware access for internal requests for KCS and SMIC. In
particular, updates to the watchdog should no longer sleep.
- Add a new IPMI_IO_LOCK for low-level I/O access. Use this for
k

Use direct hardware access for internal requests for KCS and SMIC. In
particular, updates to the watchdog should no longer sleep.
- Add a new IPMI_IO_LOCK for low-level I/O access. Use this for
kcs_polled_request() and smic_polled_request().
- Add a new backend callback "ipmi_driver_request" to handle a driver
request. The new callback performs the request sychronously for KCS
and SMIC. SSIF still defers the work to the worker thread since the
worker thread sleeps during request processing anyway.
- Allocate driver requests on the stack rather than using malloc().

Differential Revision: https://reviews.freebsd.org/D1723
Tested by: scottl
MFC after: 2 weeks

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Explicitly treat timeouts when waiting for IBF or OBF to change state as an
error. This fixes occasional hangs in the IPMI kcs thread when using
ipmitool locally.

MFC after: 1 week

Unlock IPMI sc while performing requests via KCS and SMIC interfaces.
It is already done in SSIF interface code.
This reduces contention/spinning reported by many users.

PR: kern/172166
Submitted b

Unlock IPMI sc while performing requests via KCS and SMIC interfaces.
It is already done in SSIF interface code.
This reduces contention/spinning reported by many users.

PR: kern/172166
Submitted by: Eric van Gyzen <eric at vangyzen.net>
MFC after: 2 weeks

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- Tweak an error message.
- Fix a buglet where && was used instead of & to test if OBF was set in
a couple of places.

MFC after: 1 week

Rename the kthread_xxx (e.g. kthread_create()) calls
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it t

Rename the kthread_xxx (e.g. kthread_create()) calls
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.

I'd LOVE to do this rename in 7.0 so that we can eventually MFC the
new kthread_xxx() calls.

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Update the ipmi(4) driver:
- Split out the communication protocols into their own files and use
a couple of function pointers in the softc that the commuication
protocols setup in their own attac

Update the ipmi(4) driver:
- Split out the communication protocols into their own files and use
a couple of function pointers in the softc that the commuication
protocols setup in their own attach routine.
- Add support for the SSIF interface (talking to IPMI over SMBus).
- Add an ACPI attachment.
- Add a PCI attachment that attaches to devices with the IPMI interface
subclass.
- Split the ISA attachment out into its own file: ipmi_isa.c.
- Change the code to probe the SMBIOS table for an IPMI entry to just use
pmap_mapbios() to map the table in rather than trying to setup a fake
resource on an isa device and then activating the resource to map in the
table.
- Make bus attachments leaner by adding attach functions for each
communication interface (ipmi_kcs_attach(), ipmi_smic_attach(), etc.)
that setup per-interface data.
- Formalize the model used by the driver to handle requests by adding an
explicit struct ipmi_request object that holds the state of a given
request and reply for the entire lifetime of the request. By bundling
the request into an object, it is easier to add retry logic to the various
communication backends (as well as eventually support BT mode which uses
a slightly different message format than KCS, SMIC, and SSIF).
- Add a per-softc lock and remove D_NEEDGIANT as the driver is now MPSAFE.
- Add 32-bit compatibility ioctl shims so you can use a 32-bit ipmitool
on FreeBSD/amd64.
- Add ipmi(4) to i386 and amd64 NOTES.

Submitted by: ambrisko (large portions of 2 and 3)
Sponsored by: IronPort Systems, Yahoo!
MFC after: 6 days

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