kernel/arm/paging: implement Modified Flag

* Introduce SWDBM flag similarly to the arm64 port
* Reuse TEX[2] for SWDBM flag which should be availble
to be used by the operating system if TEX remap
is enabled.
* Introduce SetAndClearPageTableEntryFlags for updating
accessed and modified flags atomically
* Startup sequence is handled similarly to accessed flag, i.e.
set Modified flag in initially mapped pages in bootloader and early map.
* Once the kernel initialization has progressed enough,
pages are mapped as read-only and modified flag handling is done
in the page fault handler.

Change-Id: I8f761e2c6325d1b91481abd569d5e8befded0761
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6518
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>

kernel/arm: don't set Accessed Flag when initially mapping a page

Pages should not be marked as accessed when initially mapping them.

However, there's a short interval during kernel startup when new pages
are mapped but the fault handler is not installed yet.

Therefore, we set Accessed Flag to 1 in early_map.
Once the kernel initialization has progressed enough, we start mapping
new pages with Accessed Flag set to 0.

The chicken and egg problem of initially mapping the vector page is
tackled by preallocating the vector page in the boot loader.

Change-Id: Ie3be4f81812d7a090af57e8c79420598d16182b9
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6450
Reviewed-by: Fredrik Holmqvist <fredrik.holmqvist@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>

kernel/arm: check for access flag fault in page fault handler

Change-Id: Icc782a692e5dcd861958ffea934386b4d4e569c7
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6428
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

kernel/arm: check for PXN and alignment fault in page fault handler

Change-Id: I2a863b57b1252343c9c029d1bb5af8d328558576
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5620
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

kernel/arm: clean up arch-specific defines

* align fault syndrome and fault address register naming with
ARM Architecture Reference Manual (i.e. IFSR, DFSR, IFAR, DFAR)
* move PSR bitfield defines to arch_cpu_defs.h

Change-Id: I813045eec335ffbdd75270ad5a1afb2f222f73c8
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5618
Reviewed-by: Fredrik Holmqvist <fredrik.holmqvist@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>

kernel/arm: implement entering userspace

Change-Id: Icf3945db979a8f4444856fc7157649f48b297c29
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5037
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Fredrik Holmqvist <fredrik.holmqvist@gmail.com>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

kernel/arm: implement prefetch abort handler

Change-Id: I39c330a44ad36ede41c7727017dd733d07288be9
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4983
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Fredrik Holmqvist <fredrik.holmqvist@gmail.com>

kernel/arm: detect read/write access in data abort handler

Use Data Fault Status Register's bit 11 to initialize isWrite.

see: ARMv7 Architecture Reference Manual,section B3.9.5
Distinguishing read and write accesses on Data Abort exceptions

Change-Id: I7da6702fc0e9579e5cb09cba3c5c89f004ec268a
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4972
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

Added private system arch specific arch_cpu_defs.h header, currently defining
only a SPINLOCK_PAUSE() macro.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36351 a95241bf-73f2-0310-859d-f6bbb57e9c96

Added private system arch specific arch_cpu_defs.h header, currently defining
only a SPINLOCK_PAUSE() macro.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36351 a95241bf-73f2-0310-859d-f6bbb57e9c96