kernel/riscv64: remove unused code

Change-Id: Ia140c962b3ae70faac3c9ae19125b0e245326586
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6743
Reviewed-by: waddlesplash <waddlesplash@gmail.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>

kernel: fully remove arch_check_syscall_restart

Currently there are only stub implementations that are never used.

Change-Id: I00dc42cad7d24f40761b93e325d3df8683745b57
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6441
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

kernel/thread: Refactor thread-local-storage initialization and updating.

* TLS slots are not in any way architecture-specific; we do not even
have a mechanism by which they could be made so at present.
Thus, the initialization of them can be moved to common code, and
out of the per-architecture implementations.

* When dealing with a fork()ed thread, it will already have a TLS array
with values set in it. Therefore, do not overwrite the whole array,
but instead only update the specific values which have changed on fork.
This fixes at least part of #17896.

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/riscv64: fix crash on userland thread exit

Set first stack frame return address to
<commpage>commpage_thread_exit, so it will be called
when thread entry point returns.

Change-Id: Ide5cde8d4501eb7241e03ff4052174e984e78870
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4493
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>

kernel/arch/thread: implement for riscv64

Change-Id: I3effa598626b32c29606299cd0edee390d430baf
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4066
Reviewed-by: Alex von Gluck IV <kallisti5@unixzen.com>

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>