Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

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

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

MFppc64:

Kernel sources for 64-bit PowerPC, along with build-system changes to keep
32-bit kernels compiling (build system changes for 64-bit kernels are
coming later). Existing 32-bit PowerPC kernel configurations must be
updated after this change to specify their architecture.

Allow the cacheline size on PowerPC to be set at runtime. This is essential for
supporting 64-bit CPUs, which often have 128-byte cache lines instead of the
standard 32.

Add kdb_cpu_sync_icache(), intended to synchronize instruction
caches with data caches after writing to memory. This typically
is required to make breakpoints work on ia64 and powerpc. For
those architectures the function is implemented.

/* -> /*- for license, minor formatting changes

Use __FBSDID rather than rcsid[].

Add sync before isync for G4 cpus

Obtained from: NetBSD
Approved by: benno

Remove __P.

Reveiwed by: benno

Bring in NetBSD code used in the PowerPC port.

Reviewed by: obrien, dfr
Obtained from: NetBSD