Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Purge mergeinfo in sys/ that is either empty or a subset of the parent
mergeinfo on sys/ itself.

Approved by: re (mergeinfo blanket)

Integrate user/mav/ata branch:

Add ch_suspend/ch_resume methods for PCI controllers and implement them
for AHCI. Refactor AHCI channel initialization according to it.

Fix Port Multipliers operation. It is far from perfect yet, but works now.
Tested with JMicron JMB363 AHCI + SiI 3726 PMP pair.
Previous version was also tested with SiI 4726 PMP.

Hardware sponsored by: Vitsch Electronics / VEHosting.nl

Add in forgotten module ipmi_linux.

Found by: mlaier

Add stuff to support upcoming BMC/IPMI flashing of newer Dell machine
via the Linux tool.
- Add Linux shim to ipmi(4)
- Create a partitions file to linprocfs to make Linux fdisk see
disks. This file is dynamic so we can see disks come and go.
- Convert msdosfs to vfat in mtab since Linux uses that for
msdosfs.
- In the Linux mount path convert vfat passed in to msdosfs
so Linux mount works on FreeBSD. Note that tasting works
so that if da0 is a msdos file system
/compat/linux/bin/mount /dev/da0 /mnt
works.
- fix a 64it bug for l_off_t.
Grabing sh, mount, fdisk, df from Linux, creating a symlink of mtab to
/compat/linux/etc/mtab and then some careful unpacking of the Linux bmc
update tool and hacking makes it work on newer Dell boxes. Note, probably
if you can't figure out how to do this, then you probably shouldn't be
doing it :-)

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

Add an OpenIPMI mostly compatible driver. This driver was developed
to work with ipmitools. It works with other tools that have an OpenIPMI
driver interface. The port will need to get updated to used this.
I have not implemented the IPMB mode yet so ioctl's for that don't
really do much otherwise it should work like the OpenIPMI version.
The ipmi.h definitions was derived from the ipmitool header file.
The bus attachments are done for smbios and pci/smbios. Differences
in bus probe order for modules/static are delt with. ACPI attachment
should be done.

This drivers registers with the watchdod(4) interface

Work to do:
- BT interface
- IPMB mode

This has been tested on Dell PE2850, PE2650 & PE850 with i386 & amd64
kernel.

I will link this into the build on next week.

Tom Rhodes, helped me with the man page.

Sponsored by: IronPort Systems Inc.
Inspired from: ipmitool & Linux