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

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

Merge from vmobj-rwlock branch:
Remove unused inclusion of vm/vm_pager.h and vm/vnode_pager.h.

Sponsored by: EMC / Isilon storage division
Tested by: pho
Reviewed by: alc

Remove platform APIs which are not used by any code and which had only stub
implementations or no implementation on all platforms.

Some of these functions might be good ideas, but their semantics were unclear
given the lack of implementation, and an unlucky porter could be fooled into
trying to implement them or, worse, being baffled when something like
platform_trap_enter() failed to be called.

At the risk of reducing source compatibility with old NetBSD and Sprite:
o) Get rid of some unused macros related to features we don't intend to
provide.
o) Get rid of macro definitions for MIPS-I CPUs. We are not likely to
support anything that predartes MIPS-III.
o) Respell MIPS3_* macros as MIPS_*, which is how most of them were being
used already.
o) Eliminate a duplicate and mostly-unused set of exception vector macros.

There's still considerable duplication and lots more obsolete in our headers,
but this reduces one of the larger files to a size where one could reckon
about the correctness of its contents with a mere few hours of contemplation.

There is, of course, a question of whether we need definitions for fields,
registers and configurations that we are unlikely to ever use or implement,
even if they're not obsolete since 1991. FreeBSD is not a processor
reference manual, and things that aren't used may be wrong, or may be
duplicated because nobody could possibly actually know whether they're
already defined.

Remove duplicate header includes

- dump_avail layout should be sequence of [start, end)
pairs, not <start, size>.

Spotted by: alc@

- Populate dump_avail with proper values from phys_avail

Make the meaning of the 'mask' argument to 'set_intr_mask(mask)' consistent
with the meaning of IM bits in the status register.

Reviewed by: jmallett, jchandra

uint64_t is 'unsigned long' in n64 build, so compiler is unhappy if the
format specifier in printf is "%llu".

Use "%ju" instead.

Fix a race between clock_intr() and tick_ticker() when updating
'counter_upper' and 'counter_lower_last'. The race exists because
interrupts are enabled even though tick_ticker() executes in a
critical section.

Fix a bug in clock_intr() in how it updates the cached values of
'counter_upper' and 'counter_lower_last'. They are updated only
when the COUNT register rolls over. More interestingly it will *never*
update the cached values if 'counter_lower_last' happens to be zero.

Get rid of superfluous critical section in clock_intr(). There is no
reason to do this because clock_intr() executes in hard interrupt
context.

Switch back to using 'tick_ticker()' as the cpu ticker for Sibyte.

Reviewed by: jmallett, mav

Remove redunant machine/cpuregs.h include.
Also, spell things like in machine/cpuregs.h instead of machine/cpu.h.

Fix Sibyte SMP kernel breakage caused by r208249.

We need to include the header file that provides declaration of the
smp_topo_none() function.

Adds JC's cleanup patches that fix it so
we call an platform dependant topo function as
well as clean up all the XLR specific ifdefs around
smp platform init.

Obtained from: JC

o) Remove default MAXMEM on SWARM; pmap can readily use lmem for >512M
physical addresses.
o) Set a local maxmem in sb_machdep.c to avoid trying to use pages over 2^64
under 32-bit ABIs. Our pmap needs corrected to use vm_paddr_t consistently,
then we can make vm_paddr_t 64-bit under 32-bit ABIs and add code in pmap
to limit phys_avail by the maximum PFN that a 32-bit PTE can hold.

Sibyte provides a 64-bit read-only counter that counts at half the processor
frequency. This counter can be accessed coherently from both cores.

Use this as the preferred timecounter for the SWARM kernels.

The CP0 COUNT register is unusable as the timecounter on SMP platforms because
the COUNT registers on different CPUs are not guaranteed to be in sync.

Add support for CPUs with cache coherent DMA. The two main changes are:

- We don't need to fall back to uncacheable memory to satisfy BUS_DMA_COHERENT
requests on these CPUs.

- The bus_dmamap_sync() is a no-op for these CPUs.

A side-effect of this change is rename DMAMAP_COHERENT flag to
DMAMAP_UNCACHEABLE. This conveys the purpose of the flag more accurately.

Reviewed by: gonzo, imp

SMP support for the mips port.

The platform that supports SMP currently is a SWARM with a dual-core Sibyte
processor. The kernel config file to use is SWARM_SMP.

Reviewed by: imp, rrs

Initialize interrupt controller early on.

Install the XTLB exception handler for Sibyte processors.

This is a workaround for the fact that the CFE is compiled as a 64-bit
application and therefore sets the SR_KX bit every time we call into
it (for e.g. console).

A TLB miss for any address above 0xc0000000 with the SR_KX bit set will
end up at the XTLB exception vector. We workaround this by copying the
standard TLB handler at the XTLB exception vector.

Approved by: imp (mentor)

- Call post-boot fixup function in order to get proper static
symbols resolving in DDB
- When zeroing .bss/.sbss do not round end address to page boundary,
it's not neccessary and might destroy data pased by trampoline or
boot loader

Remove Sibyte specific code from locore.S that sets the k0seg coherency.

Move it to platform_start() instead.

Approved by: imp (mentor)

Merge from projects/mips to head by hand:

Copy the files for the sibyte support (except files in sys/conf and
sys/mips/conf). This targets the Broadcom SWARM board (bcm91250) and
the SB-1 core in the BCM1250 SoC. This work was done by Neel Natu.

Rename mips_pcpu_init to mips_pcpu0_init since it applies only to the
BSP. Provide a missing prototype.

Centralize initialization of pcpu, and set curthread early...

Remove all CFE-specific code from locore.S. The CFE entrypoint initialization
is now done in platform-specific code.

Approved by: imp (mentor)

With this commit our friend RMI will now compile. I have
not tested it and the chances of it running yet are about
ZERO.. but it will now compile. The hard part now begins,
making it run ;-)

Add sibyte device support.

Submitted by: Neelkanth Natu