Sync up with head up to r289211.

Remerge as previous one was broken

Merge ^/head r288197 through r288456.

An IPI must be cleared before it is handled otherwise next IPI could be
missed. In other words, if a new request for an IPI is sent while the
previous request is being handled but the IPI is not clea

An IPI must be cleared before it is handled otherwise next IPI could be
missed. In other words, if a new request for an IPI is sent while the
previous request is being handled but the IPI is not cleared yet, the
clearing of the previous IPI request also clears the new one and the
handling is missed.

There are only three MP interrupt controllers in ARM now. Two of them are
fixed by this change, the third one is correct, probably only just by
accident. The fix is minimalistic as new interrupt framework is awaited.

It was debugged on RPi2 where missing IPI handling together with SCHED_ULE
led to situation in which tdq_ipipending was not cleared and so IPI_PREEMPT
was stopped to be sent. Various odditys were found related to slow system
response time like various events timed out, and slow console response.

Submitted by: Svatopluk Kraus <onwahe@gmail.com>
Reviewed by: loos, kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D3722

show more ...

Catch up with HEAD (r280229-r284686).

MFH: r282615-r283655

Sponsored by: The FreeBSD Foundation

Merge sync of head

Fix the SMP initialization on RPi 2 (BCM2836).

Invalidate the CPU cache before start the others CPUs.

Submitted by: Michal Meloun <meloun@miracle.cz>

Merge from HEAD

Add the SMP support for Raspberry Pi 2 (BCM2836).

Tested with the build of some ports and a buildworld.

Submitted by: Daisuke Aoyama <aoyama@peach.ne.jp>