riscv64/mmu: use struct bitfield for flags and std::atomic

Fixes some PTE concurrent access bugs.

Change-Id: I09ec56861fae389a8a3e228b17a3921b85202c8b
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6949
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>

mmu/riscv64: implement global page mapping support

ASID allocation is not supported yet, so always use ASID 0 for user pages for now.

Change-Id: I021e77dae692c22984bc625dd0588362bece45b7
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6698
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>

vm: Replace the VMAreas OpenHashTable with an AVLTree.

Since we used a hash table with a fixed size (1024), collisions were
obviously inevitable, meaning that while insertions would always be
fast, lookups and deletions would take linear time to search the
linked-list for the area in question. For recently-created areas,
this would be fast; for less-recently-created areas, it would get
slower and slower and slower.

A particularly pathological case was the "mmap/24-1" test from the
Open POSIX Testsuite, which creates millions of areas until it hits
ENOMEM; it then simply exits, at which point it would run for minutes
and minutes in the kernel team deletion routines; how long I don't know,
as I rebooted before it finished.

This change fixes that problem, among others, at the cost of increased
area creation time, by using an AVL tree instead of a hash. For comparison,
mmap'ing 2 million areas with the "24-1" test before this change took
around 0m2.706s of real time, while afterwards it takes about 0m3.118s,
or around a 15% increase (1.152x).

On the other hand, the total test runtime for 2 million areas went from
around 2m11.050s to 0m4.035s, or around a 97% decrease (0.031x); in other
words, with this new code, it is *32 times faster.*

Area insertion will no longer be O(1), however, so the time increase
may go up with the number of areas present on the system; but if it's
only around 3 seconds to create 2 million areas, or about 1.56 us per area,
vs. 1.35 us before, I don't think that's worth worrying about.

My nonscientific "compile HaikuDepot with 2 cores in VM" benchmark
seems to be within the realm of "noise", anyway, with most results
both before and after this change coming in around 47s real time.

Change-Id: I230e17de4f80304d082152af83db8bd5abe7b831

riscv: use atomic CSR bit set/clear operations, refactor

Fix race conditions that cause broken timer interrupts.

Change-Id: I78e13a18d394b1566977e894a1def16a66c9ca5f
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5883
Reviewed-by: X512 <danger_mail@list.ru>
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>

riscv64/smp: Implement multi-processor support

* Working under qemu smp 1,2+
* Working on SiFive Unmatched
* x86_64 efi not broken by smp_boot_other_cpus change

Change-Id: I32ebc17913e46ed082be9ade8f56448bbf12f16e
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4705
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>

kernel/arch/vm: implement for riscv64

Change-Id: I0b463f3d2bca9f31b0aabacbf70a9774493d3467
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4051
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>

kernel: arch_vm_set_memory_type takes a phys_addr_t now

Change-Id: I94a8f8453238a9ed2b2ac549d9b500c83e6c53b8

riscv64: Fill in more bulk architecture items around libroot/kernel

Change-Id: Ia2a86d8814d06950ea2d2d19d966c642d26f81d6
Reviewed-on: https://review.haiku-os.org/c/1302
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>