Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

MFC r304052:

Add missing pmap_kremove() method for book-e.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Implement pmap_change_attr() for PowerPC (Book-E only for now)

Summary:
Some drivers need special memory requirements. X86 solves this with a
pmap_change_attr() API, which DRM uses for changing the mapping of the GART and
other memory regions. Implement the same function for PowerPC. AIM currently
does not need this, but will in the future for DRM, so a default is added for
that, for business as usual. Book-E has some drivers coming down that do
require non-default memory coherency. In this case, the Datapath Acceleration
Architecture (DPAA) based ethernet controller has 2 regions for the buffer
portals: cache-inhibited, and cache-enabled. By default, device memory is
cache-inhibited. If the cache-enabled memory regions are mapped
cache-inhibited, an alignment exception is thrown on access.

Test Plan:
Tested with a new driver to be added after this (DPAA dTSEC ethernet driver).
No alignment exceptions thrown, driver works as expected with this.

Reviewed By: nwhitehorn
Sponsored by: Alex Perez/Inertial Computing
Differential Revision: https://reviews.freebsd.org/D5471

Extend Book-E to support >4GB RAM

Summary:
With some additional changes for AIM, that could also support much
larger physmem sizes. Given that 32-bit AIM is more or less obsolete, though,
it's not worth it at this time.

Differential Revision: https://reviews.freebsd.org/D4345

pmap_mapdev_attr() also takes a vm_paddr_t.

This was missed in r235936. With recent work for 36-bit paddr, this is now
needed.

Add two new pmap functions:
vm_offset_t pmap_quick_enter_page(vm_page_t m)
void pmap_quick_remove_page(vm_offset_t kva)

These will create and destroy a temporary, CPU-local KVA mapping of a specified page.

Guarantees:
--Will not sleep and will not fail.
--Safe to call under a non-sleepable lock or from an ithread

Restrictions:
--Not guaranteed to be safe to call from an interrupt filter or under a spin mutex on all platforms
--Current implementation does not guarantee more than one page of mapping space across all platforms. MI code should not make nested calls to pmap_quick_enter_page.
--MI code should not perform locking while holding onto a mapping created by pmap_quick_enter_page

The idea is to use this in busdma, for bounce buffer copies as well as virtually-indexed cache maintenance on mips and arm.

NOTE: the non-i386, non-amd64 implementations of these functions still need review and testing.

Reviewed by: kib
Approved by: kib (mentor)
Differential Revision: http://reviews.freebsd.org/D3013

Factor out duplicated code from dumpsys() on each architecture into generic
code in sys/kern/kern_dump.c. Most dumpsys() implementations are nearly
identical and simply redefine a number of constants and helper subroutines;
a generic implementation will make it easier to implement features around
kernel core dumps. This change does not alter any minidump code and should
have no functional impact.

PR: 193873
Differential Revision: https://reviews.freebsd.org/D904
Submitted by: Conrad Meyer <conrad.meyer@isilon.com>
Reviewed by: jhibbits (earlier version)
Sponsored by: EMC / Isilon Storage Division

Change pmap_enter(9) interface to take flags parameter and superpage
mapping size (currently unused). The flags includes the fault access
bits, wired flag as PMAP_ENTER_WIRED, and a new flag
PMAP_ENTER_NOSLEEP to indicate that pmap should not sleep.

For powerpc aim both 32 and 64 bit, fix implementation to ensure that
the requested mapping is created when PMAP_ENTER_NOSLEEP is not
specified, in particular, wait for the available memory required to
proceed.

In collaboration with: alc
Tested by: nwhitehorn (ppc aim32 and booke)
Sponsored by: The FreeBSD Foundation and EMC / Isilon Storage Division
MFC after: 2 weeks

Retire pmap_change_wiring(). We have never used it to wire virtual pages.
We continue to use pmap_enter() for that. For unwiring virtual pages, we
now use pmap_unwire(), which unwires a range of virtual addresses instead
of a single virtual page.

Sponsored by: EMC / Isilon Storage Division

Implement pmap_unwire(). See r268327 for the motivation behind this change.

The pmap function pmap_clear_reference() is no longer used. Remove it.

pmap_clear_reference() has had exactly one caller in the kernel for
several years, more precisely, since FreeBSD 8. Now, that call no
longer exists.

Approved by: re (kib)
Sponsored by: EMC / Isilon Storage Division

Significantly reduce the cost, i.e., run time, of calls to madvise(...,
MADV_DONTNEED) and madvise(..., MADV_FREE). Specifically, introduce a new
pmap function, pmap_advise(), that operates on a range of virtual addresses
within the specified pmap, allowing for a more efficient implementation of
MADV_DONTNEED and MADV_FREE. Previously, the implementation of
MADV_DONTNEED and MADV_FREE relied on per-page pmap operations, such as
pmap_clear_reference(). Intuitively, the problem with this implementation
is that the pmap-level locks are acquired and released and the page table
traversed repeatedly, once for each resident page in the range
that was specified to madvise(2). A more subtle flaw with the previous
implementation is that pmap_clear_reference() would clear the reference bit
on all mappings to the specified page, not just the mapping in the range
specified to madvise(2).

Since our malloc(3) makes heavy use of madvise(2), this change can have a
measureable impact. For example, the system time for completing a parallel
"buildworld" on a 6-core amd64 machine was reduced by about 1.5% to 2.0%.

Note: This change only contains pmap_advise() implementations for a subset
of our supported architectures. I will commit implementations for the
remaining architectures after further testing. For now, a stub function is
sufficient because of the advisory nature of pmap_advise().

Discussed with: jeff, jhb, kib
Tested by: pho (i386), marcel (ia64)
Sponsored by: EMC / Isilon Storage Division

Implement the concept of the unmapped VMIO buffers, i.e. buffers which
do not map the b_pages pages into buffer_map KVA. The use of the
unmapped buffers eliminate the need to perform TLB shootdown for
mapping on the buffer creation and reuse, greatly reducing the amount
of IPIs for shootdown on big-SMP machines and eliminating up to 25-30%
of the system time on i/o intensive workloads.

The unmapped buffer should be explicitely requested by the GB_UNMAPPED
flag by the consumer. For unmapped buffer, no KVA reservation is
performed at all. The consumer might request unmapped buffer which
does have a KVA reserve, to manually map it without recursing into
buffer cache and blocking, with the GB_KVAALLOC flag.

When the mapped buffer is requested and unmapped buffer already
exists, the cache performs an upgrade, possibly reusing the KVA
reservation.

Unmapped buffer is translated into unmapped bio in g_vfs_strategy().
Unmapped bio carry a pointer to the vm_page_t array, offset and length
instead of the data pointer. The provider which processes the bio
should explicitely specify a readiness to accept unmapped bio,
otherwise g_down geom thread performs the transient upgrade of the bio
request by mapping the pages into the new bio_transient_map KVA
submap.

The bio_transient_map submap claims up to 10% of the buffer map, and
the total buffer_map + bio_transient_map KVA usage stays the
same. Still, it could be manually tuned by kern.bio_transient_maxcnt
tunable, in the units of the transient mappings. Eventually, the
bio_transient_map could be removed after all geom classes and drivers
can accept unmapped i/o requests.

Unmapped support can be turned off by the vfs.unmapped_buf_allowed
tunable, disabling which makes the buffer (or cluster) creation
requests to ignore GB_UNMAPPED and GB_KVAALLOC flags. Unmapped
buffers are only enabled by default on the architectures where
pmap_copy_page() was implemented and tested.

In the rework, filesystem metadata is not the subject to maxbufspace
limit anymore. Since the metadata buffers are always mapped, the
buffers still have to fit into the buffer map, which provides a
reasonable (but practically unreachable) upper bound on it. The
non-metadata buffer allocations, both mapped and unmapped, is
accounted against maxbufspace, as before. Effectively, this means that
the maxbufspace is forced on mapped and unmapped buffers separately.
The pre-patch bufspace limiting code did not worked, because
buffer_map fragmentation does not allow the limit to be reached.

By Jeff Roberson request, the getnewbuf() function was split into
smaller single-purpose functions.

Sponsored by: The FreeBSD Foundation
Discussed with: jeff (previous version)
Tested by: pho, scottl (previous version), jhb, bf
MFC after: 2 weeks

Add pmap function pmap_copy_pages(), which copies the content of the
pages around, taking array of vm_page_t both for source and
destination. Starting offsets and total transfer size are specified.

The function implements optimal algorithm for copying using the
platform-specific optimizations. For instance, on the architectures
were the direct map is available, no transient mappings are created,
for i386 the per-cpu ephemeral page frame is used. The code was
typically borrowed from the pmap_copy_page() for the same
architecture.

Only i386/amd64, powerpc aim and arm/arm-v6 implementations were
tested at the time of commit. High-level code, not committed yet to
the tree, ensures that the use of the function is only allowed after
explicit enablement.

For sparc64, the existing code has known issues and a stab is added
instead, to allow the kernel linking.

Sponsored by: The FreeBSD Foundation
Tested by: pho (i386, amd64), scottl (amd64), ian (arm and arm-v6)
MFC after: 2 weeks

Fix physical address type to vm_paddr_t.

Replace the list of PVOs owned by each PMAP with an RB tree. This simplifies
range operations like pmap_remove() and pmap_protect() as well as allowing
simple operations like pmap_extract() not to involve any global state.
This substantially reduces lock coverages for the global table lock and
improves concurrency.

As it turns out, r186347 actually is insufficient to avoid the use of the
curthread-accessing part of mtx_{,un}lock(9) when using a r210623-style
curthread implementation on sparc64, crashing the kernel in its early
cycles as PCPU isn't set up, yet (and can't be set up as OFW is one of the
things we need for that, which leads to a chicken-and-egg problem). What
happens is that due to the fact that the idea of r210623 actually is to
allow the compiler to cache invocations of curthread, it factors out
obtaining curthread needed for both mtx_lock(9) and mtx_unlock(9) to
before the branch based on kobj_mutex_inited when compiling the kernel
without the debugging options. So change kobj_class_compile_static(9)
to just never acquire kobj_mtx, effectively restricting it to its
documented use, and add a kobj_init_static(9) for initializing objects
using a class compiled with the former and that also avoids using mutex(9)
(and malloc(9)). Also assert in both of these functions that they are
used in their intended way only.
While at it, inline kobj_register_method() and kobj_unregister_method()
as there wasn't much point for factoring them out in the first place
and so that a reader of the code has to figure out the locking for
fewer functions missing a KOBJ_ASSERT.
Tested on powerpc{,64} by andreast.

Reviewed by: nwhitehorn (earlier version), jhb
MFC after: 3 days

Fix some KTR arguments that were breaking the LINT build.

Pointy hat to: me

Add support for memory attributes (pmap_mapdev_attr() and friends) on
PowerPC/AIM. This is currently stubbed out on Book-E, since I have no
idea how to implement it there.

Roughly half of a typical pmap_mincore() implementation is machine-
independent code. Move this code into mincore(), and eliminate the
page queues lock from pmap_mincore().

Push down the page queues lock into pmap_clear_modify(),
pmap_clear_reference(), and pmap_is_modified(). Assert that these
functions are never passed an unmanaged page.

Eliminate an inaccurate comment from powerpc/powerpc/mmu_if.m:
Contrary to what the comment says, pmap_mincore() is not simply an
optimization. Without a complete pmap_mincore() implementation,
mincore() cannot return either MINCORE_MODIFIED or MINCORE_REFERENCED
because only the pmap can provide this information.

Eliminate the page queues lock from vfs_setdirty_locked_object(),
vm_pageout_clean(), vm_object_page_collect_flush(), and
vm_object_page_clean(). Generally speaking, these are all accesses
to the page's dirty field, which are synchronized by the containing
vm object's lock.

Reduce the scope of the page queues lock in vm_object_madvise() and
vm_page_dontneed().

Reviewed by: kib (an earlier version)

Resurrect pmap_is_referenced() and use it in mincore(). Essentially,
pmap_ts_referenced() is not always appropriate for checking whether or
not pages have been referenced because it clears any reference bits
that it encounters. For example, in mincore(), clearing the reference
bits has two negative consequences. First, it throws off the activity
count calculations performed by the page daemon. Specifically, a page
on which mincore() has called pmap_ts_referenced() looks less active
to the page daemon than it should. Consequently, the page could be
deactivated prematurely by the page daemon. Arguably, this problem
could be fixed by having mincore() duplicate the activity count
calculation on the page. However, there is a second problem for which
that is not a solution. In order to clear a reference on a 4KB page,
it may be necessary to demote a 2/4MB page mapping. Thus, a mincore()
by one process can have the side effect of demoting a superpage
mapping within another process!

o Introduce vm_sync_icache() for making the I-cache coherent with
the memory or D-cache, depending on the semantics of the platform.
vm_sync_icache() is basically a wrapper around pmap_sync_icache(),
that translates the vm_map_t argumument to pmap_t.
o Introduce pmap_sync_icache() to all PMAP implementation. For powerpc
it replaces the pmap_page_executable() function, added to solve
the I-cache problem in uiomove_fromphys().
o In proc_rwmem() call vm_sync_icache() when writing to a page that
has execute permissions. This assures that when breakpoints are
written, the I-cache will be coherent and the process will actually
hit the breakpoint.
o This also fixes the Book-E PMAP implementation that was missing
necessary locking while trying to deal with the I-cache coherency
in pmap_enter() (read: mmu_booke_enter_locked).

The key property of this change is that the I-cache is made coherent
*after* writes have been done. Doing it in the PMAP layer when adding
or changing a mapping means that the I-cache is made coherent *before*
any writes happen. The difference is key when the I-cache prefetches.

Factor out platform dependent things unrelated to device drivers into a
new platform module. These are probed in early boot, and have the
responsibility of determining the layout of physical memory, determining
the CPU timebase frequency, and handling the zoo of SMP mechanisms
found on PowerPC.

Reviewed by: marcel, raj
Book-E parts by: raj

PowerPC, meet kernel core dumps. The support is based
on a generic dumper that creates an ELF core file and
uses PMAP functions to scan and iterate over memory
chunks, as well as handle memory mappings used during
dumping.
the PMAP layer can choose to return physical memory
chunks or virtual memory chunks. For minidumps, the
chunks should be virtual.

The default MMU I/F implementation for the scan_md()
method returns NULL. Thus, when a PMAP implementation
does not implement the required methods, an empty
core file is created. Here, empty means having an ELF
header only.

Obtained from: Juniper Networks

Add support for 64-bit PowerPC CPUs operating in the 64-bit bridge mode
provided, for example, on the PowerPC 970 (G5), as well as on related CPUs
like the POWER3 and POWER4.

This also adds support for various built-in hardware found on Apple G5
hardware (e.g. the IBM CPC925 northbridge).

Reviewed by: grehan

Modularize the Open Firmware client interface to allow run-time switching
of OFW access semantics, in order to allow future support for real-mode
OF access and flattened device frees. OF client interface modules are
implemented using KOBJ, in a similar way to the PPC PMAP modules.

Because we need Open Firmware to be available before mutexes can be used on
sparc64, changes are also included to allow KOBJ to be used very early in
the boot process by only using the mutex once we know it has been initialized.

Reviewed by: marius, grehan

Trace all PMAP calls using KTR_PMAP.

Retire pmap_addr_hint(). It is no longer used.

Add a stub for pmap_align_superpage() on machines that don't (yet)
implement pmap-level support for superpages.

Add an access type parameter to pmap_enter(). It will be used to implement
superpage promotion.

Correct a style error in kmem_malloc(): pmap_enter()'s last parameter is
a Boolean.

Prevent the leakage of wired pages in the following circumstances:
First, a file is mmap(2)ed and then mlock(2)ed. Later, it is truncated.
Under "normal" circumstances, i.e., when the file is not mlock(2)ed, the
pages beyond the EOF are unmapped and freed. However, when the file is
mlock(2)ed, the pages beyond the EOF are unmapped but not freed because
they have a non-zero wire count. This can be a mistake. Specifically,
it is a mistake if the sole reason why the pages are wired is because of
wired, managed mappings. Previously, unmapping the pages destroys these
wired, managed mappings, but does not reduce the pages' wire count.
Consequently, when the file is unmapped, the pages are not unwired
because the wired mapping has been destroyed. Moreover, when the vm
object is finally destroyed, the pages are leaked because they are still
wired. The fix is to reduce the pages' wired count by the number of
wired, managed mappings destroyed. To do this, I introduce a new pmap
function pmap_page_wired_mappings() that returns the number of managed
mappings to the given physical page that are wired, and I use this
function in vm_object_page_remove().

Reviewed by: tegge
MFC after: 6 weeks

Fix for the panic("vm_thread_new: kstack allocation failed") and
silent NULL pointer dereference in the i386 and sparc64 pmap_pinit()
when the kmem_alloc_nofault() failed to allocate address space. Both
functions now return error instead of panicing or dereferencing NULL.

As consequence, vmspace_exec() and vmspace_unshare() returns the errno
int. struct vmspace arg was added to vm_forkproc() to avoid dealing
with failed allocation when most of the fork1() job is already done.

The kernel stack for the thread is now set up in the thread_alloc(),
that itself may return NULL. Also, allocation of the first process
thread is performed in the fork1() to properly deal with stack
allocation failure. proc_linkup() is separated into proc_linkup()
called from fork1(), and proc_linkup0(), that is used to set up the
kernel process (was known as swapper).

In collaboration with: Peter Holm
Reviewed by: jhb

Fix gdb issue where the i-cache was not being updated when a breakpoint
was written into a user's address space. The fix is to modify uiomove_fromphys
to sync the icache when an executable user-space page is written into.

Alan Cox suggested that there should probably be a higher-level interface
to this in the ptrace code, but agreed that this is an OK short-term solution.

Files changed:

pmap.h - declaration of pmap_page_executable()
pmap_dispatch.c - pass through the page_executable call to the mmu object
mmu_oea.c - implement the page_executable method by examining the PTE_EXEC
field in the vm_page_t
uio_machdep.c - in uiomove_fromphys(), if the op was a UIO_WRITE to user-space,
and if the page is executable, sync the icache since this is at the least
a breakpoint-write from gdb.

Reported by: marcel
Tested by: marcel, grehan on g3+g4
Discussed with: alc
MFC after: 2 weeks

Eliminate unused global variables.

Complete the transition from pmap_page_protect() to pmap_remove_write().
Originally, I had adopted sparc64's name, pmap_clear_write(), for the
function that is now pmap_remove_write(). However, this function is more
like pmap_remove_all() than like pmap_clear_modify() or
pmap_clear_reference(), hence, the name change.

The higher-level rationale behind this change is described in
src/sys/amd64/amd64/pmap.c revision 1.567. The short version is that I'm
trying to clean up and fix our support for execute access.

Reviewed by: marcel@ (ia64)

Remove mpte optimization from pmap_enter_quick().
There is a race with the current locking scheme and removing
it should have no measurable performance impact.
This fixes page faults leading to panics in pmap_enter_quick_locked()
on amd64/i386.

Reviewed by: alc,jhb,peter,ps

Add a stub for pmap_enter_object().

Remove the unused sva and eva arguments from pmap_remove_pages().

Eliminate pmap_init2(). It's no longer used.

Apply r1.103 to correct place.

pmap.c on PowerPC is now a combo of mmu_if.m, pmap_dispatch.c
and mmu_oea.c

(I forgot to delete pmap.c from CVS in last jumbo commit)

Insert a layer of indirection to the pmap code, using a kobj for
the interface. This allows run-time selection of MMU code, based
on CPU-type detection, or tunable-overrides when testing new code.

Pre-requisite for G5 support.

conf/files.powerpc
- remove pmap.c
- add mmu_if.h, mmu_oea.c, pmap_dispatch.c

powerpc/include/mmuvar.h
- definitions for MMU implementations

powerpc/include/pmap.h
- remove pmap_pte_spill declaration
- add pmap_mmu_install declaration
- size the phys_avail array
- pmap_bootstrapped is now global-scope

powerpc/powerpc/machdep.c
- call kobj_machdep_init early in the boot sequence to allow
kobj usage prior to SI_SUB_LOCK
- install the OEA pmap code. This will be moved to CPU-specific
init code in the future.

powerpc/powerpc/mmu_if.m
- Kobj MMU interface definitions

powerpc/powerpc/pmap_dispatch.c
- central dispatch for pmap calls
- contains the global mmu kobj and the routine to locate the
the mmu implementation and init the kobj