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

MFC r258800, r258802, r258805, r258806, r258807, r258851, r258857,
r259199, r259484, r259513, r259514, r259516

The kernel stack guard pages are only below the stack pointer, not above.

Remove unnecessary double-setting of the thread's onfault state in
copyinstr().

Open Firmware mandates that certain cross-references, in particular those
in /chosen, be ihandles. The ePAPR spec makes those cross-reference phandles,
since FDT has no concept of ihandles. Have the OF FDT CI module interpret
queries about ihandles as cross-reference phandles.

Real OF systems have an ihandle under /chosen/stdout, not a phandle. Use
the right type.

Rearchitect platform memory map parsing to make it less
Open Firmware-centric.

Remove fdtbus_bs_tag definition, which is now obsolete. The remainder of
this file is also slated for future demolition.

Return the correct IEEE 1275 code for "nextprop".

Use the common Open Firmware PCI interrupt routing code instead of the
duplicate version in dev/fdt.

Configure interrupt sense based on device tree information.

Simplify the ofw_bus_lookup_imap() API slightly: make it allocate maskbuf
internally instead of requiring the caller to allocate it.

MFC r258002, r258024, r258027, r258051, r258052, r258243, r258244, r258002,
r258024, r258027, r258051, r258052, r258243,

Follow up r223485, which made AIM use the ABI thread pointer instead of
PCPU fields for curthread, by doing the same to Book-E.

Use the same implementation of copyinout.c for both AIM and Book-E.

Actually add IOMMU domain to the list of known mappings.

Following the approach with ACPI DMAR on x86, split IOMMU handling into
a variant PCI bus instead of trying to shoehorn it into the PCI host bridge
adapter.

Make sure that TLB1 mappings are aligned correctly.

Use the same implementation of copyinout.c for both AIM and Book-E. This
fixes some bugs in both implementations related to validity checks on
mapping bounds.

Use the ABI-mandated thread pointer register (r2 for ppc32, r13 for ppc64)
instead of a PCPU field for curthread. This averts a race on SMP systems
with a high interrupt rate where the thread looking up the value of
curthread could be preempted and migrated between obtaining the PCPU
pointer and reading the value of pc_curthread, resulting in curthread being
observed to be the current thread on the thread's original CPU. This played
merry havoc with the system, in particular with mutexes. Many thanks to
jhb for helping me work this one out.

Note that Book-E is in principle susceptible to the same problem, but has
not been modified yet due to lack of Book-E hardware.

MFC after: 2 weeks

Fix two mistakes on 32-bit systems. The slbmte code in syscall() is 64-bit
only, and should be protected with an ifdef, and the no-execute bit in
32-bit set_user_sr() should be set before the comparison, not after, or
it will never match.

Clean up the user segment handling code a little more. Now that
set_user_sr() itself caches the user segment VSID, there is no need for
cpu_switch() to do it again. This change also unifies the 32 and 64-bit
code paths for kernel faults on user pages and remaps the user SLB slot
on 64-bit systems when taking a syscall to avoid some unnecessary segment
exception traps.

Add a security nit to recent copyin/out changes: map the user segment
no-execute in case of exploitable kernel bugs.

MFC after: 1 week

Next-to-leading-order perturbation of synchronization operations for
switching the user segment register. All races should now be closed and
a minimum of pipelines flushes be required to close them.

Restructure the way the copyin/copyout segment is stored to prevent a
concurrency bug. Since all SLB/SR entries were invalidated during an
exception, a decrementer exception could cause the user segment to be
invalidated during a copyin()/copyout() without a thread switch that
would cause it to be restored from the PCB, potentially causing the
operation to continue on invalid memory. This is now handled by explicit
restoration of segment 12 from the PCB on 32-bit systems and a check in
the Data Segment Exception handler on 64-bit.

While here, cause copyin()/copyout() to check whether the requested
user segment is already installed, saving some pipeline flushes, and
fix the synchronization primitives around the mtsr and slbmte
instructions to prevent accessing stale segments.

MFC after: 2 weeks

Replace the SLB backing store splay tree used on 64-bit PowerPC AIM
hardware with a lockless sparse tree design. This marginally improves
the performance of PMAP and allows copyin()/copyout() to run without
acquiring locks when used on wired mappings.

Submitted by: mdf

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.

Fix a race in casuword() exposed by csup. casuword() non-atomically read
the current value of its argument before atomically replacing it, which
could occasionally return the wrong value on an SMP system. This resulted
in user mutex operations hanging when using threaded applications.

Forced commit to record that this file was repocopied from
src/sys/powerpc/powerpc and modified for its new location.

Fix remaining compile error.

Attempt to fix compiling problem.

Noticed by: tinderbox

o Add keyword volatile for user mutex owner field.
o Fix type consistent problem by using type long for old
umtx and wait channel.
o Rename casuptr to casuword.

Implement casuword32, compare and set user integer, thank Marcel Moolenarr
who wrote the IA64 version of casuword32.

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

Kernel changes for libthr (and probably libpthread).

include/ucontext.h
- remove trapframe and switch over to 'generic' description of machine
state. Include version field to help with future modifications.
Include floating point and altivec state, and hopefully align
correctly

powerpc/copyinout.c
- fill out casuptr() sync primitive, required by kern_umtx.c

powerpc/machdep.c
- shifted proc0/thread0/pcpu setup to before cninit, since
syscons -> make_dev -> devlock requires a valid curthread
- implemented get_mcontext/set_mcontext
- recast sendsig/sigreturn to use get/set_mcontext and new
ucontext struct. floating point now saved
- TODO: save/restore altivec state

powerpc/vm_machdep.c
- implemented cpu_thread_setup/cpu_set_upcall/cpu_set_upcall_kse
- eliminated trailing whitespace

Submitted by: Suleiman Souhlal <refugee@segfaulted.com>, ucontext by grehan

Cleaned up param.h:

- culled long-dead #define's
- segment register defs moved to sr.h
- NPMAPS moved to pmap.h
- KERNBASE moved to vmparam.h
- removed include of <machine/cpu.h> and fixed src files that
relied on this.

Modifying segment register code no longer causes gcc rebuilds :-)

Use __FBSDID rather than rcsid[].

Fix incorrect error returns and sign-extension.

Approved by: benno

Deorbit suibyte(). It was only used for split address space systems
for supporting UIO_USERISPACE (ie: it wasn't used).

Use correct types in [sf]uword32.

Add declarations of suword32 and suword64. Add implementations of one or
the other (or both) to all the platforms. Similar for fuword32 and
fuword64.

- Add a prototype for the setfault() function.
- Remove some stray printf()s.

- Add back calls to setfault that were removed when these functions were moved.

Collect all functions for copying to and from userspace into the one file.

This allows me to reimplement [sf]u{byte,word} as separate functions and not
as calls to copy{in,out}.