Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r249257:
Add support for getting and setting BBU properties related to battery
relearning. Specifically, add subcommands to mfiutil(8) which allow the
user to set the BBU and autolearn modes when the firmware supports it,
and add a subcommand which kicks off a battery relearn.

MFC r249258:
Switch to a 2-clause license.

MFC r237259 r237260 r237329:
Allow users with RO privilege to the device to read the RO attributes. [0]
Add __unused macros to appropriate places in order to allow building
with WARNS=6 on base gcc, gcc46, and clang

PR: bin/167302 [0]
Approved by: cperciva (implicit)

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Move the logic to parse volume cache commands out into a separate function
and use a loop so that multiple cache commands can be strung together on
the command line into a single update to the volume's properties.

Reviewed by: bz
Approved by: re (kib)
MFC after: 1 week

Contrary to when returning in all-good cases at the end of functions we
did not free memory (1) or close the file descriptor (2) in error cases.

Reported by: Mark Johnston (1)
Reported by: attilio (2)
Reviewed by: jhb
Sponsored by: Sandvine Incorporated
MFC after: 1 week

Add the ability to manage the state of write caching when the battery
back-up is missing or dead. The current state of this field is reported
in 'mfiutil cache <volume>' and can be adjusted via
'mfiutil cache <volume> bad-bbu-write-cache <enable|disable>'. This
setting should generally be disabled to avoid data loss.

MFC after: 1 week

- Save errno values before calling warn(3) so that errors are correctly
reported.
- Use powerof2() from <sys/param.h> rather than a copy and paste version.

Submitted by: gcooper
MFC after: 1 week

ntroduce mfiutil, a basic utility for managing LSI SAS-RAID & Dell PERC5/6
controllers. Controller, array, and drive status can be checked, basic
attributes can be changed, and arrays and spares can be created and deleted.
Controller firmware can also be flashed.

This does not replace MegaCLI, found in ports, as that is officially sanctioned
and supported by LSI and includes vastly more functionality. However, mfiutil
is open source and guaranteed to provide basic functionality, which can be
especially useful if you have a problem and can't get MegaCLI to work.

Approved by: re
Obtained from: Yahoo! Inc.