Commit Graph

280 Commits

Author SHA1 Message Date
Eitan Adler
caa7e52f3f kernel: Fix several typos and minor errors
- duplicate words
- typos
- references to old versions of FreeBSD

Reviewed by:	imp, benno
2017-12-27 03:23:21 +00:00
Nathan Whitehorn
d6716aa2af The highest-order bit of the bootloader cookie is 1, with the result that
the 32-bit cookie can be sign-extended on its way out of the loader and
through Open Firmware. If sign-extended, the in-kernel check of its value
would fail on 64-bit systems, resulting in a mountroot prompt. Solve this
by telling the kernel to ignore the high-order bits.

PR:		kern/224437
Submitted by:	Gustavo Romero
2017-12-19 16:45:40 +00:00
Justin Hibbits
713e844971 Retrieve the page outside of holding locks
pmap_track_page() only works with physical memory pages, which have a
constant vm_page_t address.  Microoptimize pmap_track_page() to perform one
less operation under the lock.
2017-12-10 04:43:27 +00:00
Justin Hibbits
94a9d7c3b9 Remove PTE VA mappings for tracked pages in 64-bit mode
This was done in 32-bit mode, but not duplicated when 64-bit mode was
brought in.  Without this, stale mappings can be left, leading to odd
crashes when the wrong VA is checked in XX_PhysToVirt() (dpaa(4)).
2017-12-08 03:49:53 +00:00
Justin Hibbits
3de971a61a Only check the page tables if within the KVA.
Devices aren't mapped within the KVA, and with the way 64-bit hashes the
addresses pte_vatopa() may not return a 0 physical address for a device.

MFC after:	1 week
2017-11-29 01:26:07 +00:00
Pedro F. Giffuni
71e3c3083b sys/powerpc: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 15:09:59 +00:00
Justin Hibbits
41eeef87ca Synchronize TLB1 mappings when created
This allows modules creating mappings to be loaded post-boot, after SMP has
started.  Without this, the TLB1 mappings can become unsynchronized and lead
to kernel page faults when accessed on the alternate CPUs.

MFC after:	3 weeks
2017-11-26 20:30:02 +00:00
Nathan Whitehorn
47f69f4f2b Use the cookie now set by loader to determine whether the value passed to
PowerPC kernels in r6 is actually metadata from loader(8) or gibberish
left in r6, which is not required to be anything under the
PAPR/ePAPR/CHRP/OF standards, by another boot loader.

Note that, as a result, systems need a new boot loader to boot PPC kernels
after this revision without ending up at a mountroot prompt. New boot
loaders are backwards compatible and can boot older kernels.

Reviewed by:	jhibbits
MFC after:	2 months
2017-11-26 03:53:20 +00:00
Justin Hibbits
1ccb14588b Check the page table before TLB1 in pmap_kextract()
The vast majority of pmap_kextract() calls are looking for a physical memory
address, not a device address.  By checking the page table first this saves
the formerly inevitable 64 (on e500mc and derivatives) iteration loop
through TLB1 in the most common cases.

Benchmarking this on the P5020 (e5500 core) yields a 300% throughput
improvement on dtsec(4) (115Mbit/s -> 460Mbit/s) measured with iperf.

Benchmarked on the P1022 (e500v2 core, 16 TLB1 entries) yields a 50%
throughput improvement on tsec(4) (~93Mbit/s -> 165Mbit/s) measured with
iperf.

MFC after:	1 week
Relnotes:	Maybe (significant performance improvement)
2017-11-21 03:12:16 +00:00
Justin Hibbits
2d968f6dd4 Properly initialize the full md_page structure 2017-11-10 04:23:58 +00:00
Justin Hibbits
06ba753a7a Book-E pmap_mapdev_attr() improvements
* Check TLB1 in all mapdev cases, in case the memattr matches an existing
  mapping (doesn't need to be MAP_DEFAULT).
* Fix mapping where the starting address is not a multiple of the widest size
  base.  For instance, it will now properly map 0xffffef000, size 0x11000 using
  2 TLB entries, basing it at 0x****f000, instead of 0x***00000.

MFC after:	2 weeks
2017-11-10 04:14:48 +00:00
Justin Hibbits
bc3acf82cc Clear the WE bit in C code rather than the asm
According to EREF rlwinm is supposed to clear the upper 32 bits of the
register of 64-bit cores.  However, from experience it seems there's a bug
in the e5500 which causes the result to be duplicated in the upper bits of
the register.  This causes problems when applied to stashed SRR1 accessed
to retrieve context, as the upper bits are not masked out, so a
set_mcontext() fails.  This causes sigreturn() to in turn return with
EINVAL, causing make(1) to exit with error.

This bit is unused in e500mc derivatives (including e5500), so could just be
conditional on non-powerpc64, but there may be other non-Freescale cores
which do use it.  This is also the same as the POW bit on Book-S, so could
be cleared unconditionally with the only penalty being a few clock cycles
for these two interrupts.
2017-11-08 01:23:37 +00:00
Justin Hibbits
61b9e7ef6a Fix debug interrupts on 64-bit Book-E
Use a WORD_SIZE macro to define the correct offset to the second word
needed.  This corrects the offset calculation in 64-bit builds.
2017-11-01 02:40:15 +00:00
Justin Hibbits
d41742b585 Expand the TLB nest level mask to 3 bits to match the 32-bit mask
This really doesn't change anything right now, because BOOKE_TLB_MAXNEST is only
3, which fits into the 2 bits currently used.
2017-10-20 03:31:23 +00:00
Justin Hibbits
da7266dd6b Remove an obsolete comment
This has been wrong for well over a year, we support the full 36-bit
(or more) PA space.
2017-07-05 02:20:03 +00:00
Justin Hibbits
d7fd731d06 Use the more common Book-E idiom for disabling interrupts.
Book-E has the wrteei/wrtee instructions for writing the PSL_EE bit, ignoring
all others.  Use this instead of the AIM-typical mtmsr.

MFC with:	r320392
2017-06-30 02:11:32 +00:00
Justin Hibbits
3d1357108a Disable interrupts when updating the TLB
Without disabling interrupts it's possible for another thread to preempt
and update the registers post-read (tlb1_read_entry) or pre-write
(tlb1_write_entry), and confuse the kernel with mixed register states.

MFC after:	2 weeks
2017-06-27 01:57:22 +00:00
Justin Hibbits
675cad71e7 Fix stack tracing in dtrace for powerpc
The current method only sort of works, and usually doesn't work reliably.
Also, on Book-E the return address from DEBUG exceptions is not the sentinel
addresses, so it won't exit the loop correctly.

Fix this by better handling trap frames during unwinding, and using the
common trap handler for debug traps, as the code in that segment is
identical between the two.

MFC after:	1 week
2017-05-11 00:23:51 +00:00
Justin Hibbits
e683c328f8 Introduce 64-bit PowerPC Book-E support
Extend the Book-E pmap to support 64-bit operation.  Much of this was taken from
Juniper's Junos FreeBSD port.  It uses a 3-level page table (page directory
list -- PP2D, page directory, page table), but has gaps in the page directory
list where regions will repeat, due to the design of the PP2D hash (a 20-bit gap
between the two parts of the index).  In practice this may not be a problem
given the expanded address space.  However, an alternative to this would be to
use a 4-level page table, like Linux, and possibly reduce the available address
space; Linux appears to use a 46-bit address space.  Alternatively, a cache of
page directory pointers could be used to keep the overall design as-is, but
remove the gaps in the address space.

This includes a new kernel config for 64-bit QorIQ SoCs, based on MPC85XX, with
the following notes:
* The DPAA driver has not yet been ported to 64-bit so is not included in the
  kernel config.
* This has been tested on the AmigaOne X5000, using a MD_ROOT compiled in
  (total size kernel+mdroot must be under 64MB).
* This can run both 32-bit and 64-bit processes, and has even been tested to run
  a 32-bit init with 64-bit children.

Many thanks to stevek and marcel for getting Juniper's FreeBSD patches open
sourced to be used here, and to stevek for reviewing, and providing some
historical contexts on quirks of the code.

Reviewed by:	stevek
Obtained from:	Juniper (in part)
MFC after:	2 months
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D9433
2017-03-17 21:40:14 +00:00
Justin Hibbits
27da2007da Correct the return value for pmap_change_attr()
pmap_change_attr() returns an error code, not a paddr.  This function is
currently unused for powerpc.

MFC after:	2 weeks
2017-02-21 05:08:07 +00:00
Justin Hibbits
91722a2f0f Add Book-E Enhanced Debug (E.D) profile debug support
Freescale added the E.D profile to e500mc and derivative cores.  From
Freescale's EREF reference manual this is enabled by a bit in HID0 and should
otherwise default to traditional debug.  However, none of the Freescale cores
support that bit, and instead always use E.D.  This results in kernel panics
using the standard debug on e500mc+ cores.

Enhanced debug allows debugging of interrupts, including critical interrupts,
as it uses a different save/restore registers (srr*).  At this time we don't use
this ability, so instead share the core of the debug handler code between both
handlers.

MFC after:	3 weeks
2017-02-01 03:29:13 +00:00
Justin Hibbits
0a82e6f09a Use trunc_page() instead of rolling my own in pmap_track_page() 2016-12-05 02:27:50 +00:00
Justin Hibbits
aa38c69b74 Fix a typo (move parenthesis to correct location in the line).
Before this, it would cause the one consumer of this API in powerpc usage
(dev/dpaa) to set the PTE WIMG flags to empty instead of --M-, making the
cache-enabled buffer portals non-coherent.
2016-12-04 02:15:46 +00:00
Justin Hibbits
b2f831c009 Simplify the page tracking for VA<->PA translations.
Drop the tracking down to the pmap layer, with optimizations to only track
necessary pages.  This should give a (slight) performance improvement, as well
as a stability improvement, as the tracking is already mostly handled by the
pmap layer.
2016-11-16 05:24:42 +00:00
Justin Hibbits
dc9b124d66 Create a new MACHINE_ARCH for Freescale PowerPC e500v2
Summary:
The Freescale e500v2 PowerPC core does not use a standard FPU.
Instead, it uses a Signal Processing Engine (SPE)--a DSP-style vector processor
unit, which doubles as a FPU.  The PowerPC SPE ABI is incompatible with the
stock powerpc ABI, so a new MACHINE_ARCH was created to deal with this.
Additionaly, the SPE opcodes overlap with Altivec, so these are mutually
exclusive.  Taking advantage of this fact, a new file, powerpc/booke/spe.c, was
created with the same function set as in powerpc/powerpc/altivec.c, so it
becomes effectively a drop-in replacement.  setjmp/longjmp were modified to save
the upper 32-bits of the now-64-bit GPRs (upper 32-bits are only accessible by
the SPE).

Note: This does _not_ support the SPE in the e500v1, as the e500v1 SPE does not
support double-precision floating point.

Also, without a new MACHINE_ARCH it would be impossible to provide binary
packages which utilize the SPE.

Additionally, no work has been done to support ports, work is needed for this.
This also means no newer gcc can yet be used.  However, gcc's powerpc support
has been refactored which would make adding a powerpcspe-freebsd target very
easy.

Test Plan:
This was lightly tested on a RouterBoard RB800 and an AmigaOne A1222
(P1022-based) board, compiled against the new ABI.  Base system utilities
(/bin/sh, /bin/ls, etc) still function appropriately, the system is able to boot
multiuser.

Reviewed By:	bdrewery, imp
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D5683
2016-10-22 01:57:15 +00:00
Alan Cox
8cb0c1029d Various changes to pmap_ts_referenced()
Move PMAP_TS_REFERENCED_MAX out of the various pmap implementations and
into vm/pmap.h, and describe what its purpose is.  Eliminate the archaic
"XXX" comment about its value.  I don't believe that its exact value, e.g.,
5 versus 6, matters.

Update the arm64 and riscv pmap implementations of pmap_ts_referenced()
to opportunistically update the page's dirty field.

On amd64, use the PDE value already cached in a local variable rather than
dereferencing a pointer again and again.

Reviewed by:	kib, markj
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D7836
2016-09-10 16:49:25 +00:00
Justin Hibbits
bdee3435fa Allow pmap_early_io_unmap() to reclaim memory
pmap_early_io_map()/pmap_early_io_unmap(), if used in pairs, should be used in
the form:

pmap_early_io_map()
..do stuff..
pmap_early_io_unmap()

Without other allocations in the middle.  Without reclaiming memory this can
leave large holes in the device space.

While here, make a simple change to the unmap loop which now permits it to unmap
multiple TLB entries in the range.
2016-09-07 03:26:55 +00:00
Mark Johnston
dbbaf04f1e Remove support for idle page zeroing.
Idle page zeroing has been disabled by default on all architectures since
r170816 and has some bugs that make it seemingly unusable. Specifically,
the idle-priority pagezero thread exacerbates contention for the free page
lock, and yields the CPU without releasing it in non-preemptive kernels. The
pagezero thread also does not behave correctly when superpage reservations
are enabled: its target is a function of v_free_count, which includes
reserved-but-free pages, but it is only able to zero pages belonging to the
physical memory allocator.

Reviewed by:	alc, imp, kib
Differential Revision:	https://reviews.freebsd.org/D7714
2016-09-03 20:38:13 +00:00
Justin Hibbits
60152a4037 Fix system hang when large FDT is in use
Summary:
Kernel maps only one page of FDT. When FDT is more than one page in size, data
TLB miss occurs on memmove() when FDT is moved to kernel storage
(sys/powerpc/booke/booke_machdep.c, booke_init())

This introduces a pmap_early_io_unmap() to complement pmap_early_io_map(), which
can be used for any early I/O mapping, but currently is only used when mapping
the fdt.

Submitted by:	Ivan Krivonos <int0dster_gmail.com>
Differential Revision: https://reviews.freebsd.org/D7605
2016-08-24 03:51:40 +00:00
Justin Hibbits
81ef73fb1b Take into account mas7/8 when reading/writing TLB entries on e6500
Summary: Current booke/pmap code ignores mas7 and mas8 on e6500 CPU.

Submitted by:	Ivan Krivonos <int0dster_gmail.com>
Differential Revision: https://reviews.freebsd.org/D7606
2016-08-23 04:26:30 +00:00
Justin Hibbits
beacb09864 Skip HID1 initialization on e6500 cores, it doesn't exist.
With this, and some drivers removed, a T2080 dev board boots to mountroot.

Submitted by:	Ivan Krivonos <int0dster_AT_gmail.com>
2016-08-20 00:55:58 +00:00
Justin Hibbits
791578a84f Add missing pmap_kenter() method for book-e.
This isn't added to AIM yet, because it's not yet needed.  It's needed for
Book-E ePAPR boot support.

X-MFC With:	r304047
2016-08-13 18:57:14 +00:00
Justin Hibbits
cbc3c68d9a Add a kdb show command to print arbitrary SPRs on PowerPC
Summary:
There is often a need at the debugger to print arbitrary special
purpose registers (SPRs) on PowerPC.  Using a rewritable asm stub, print any SPR
provided on the command line.

Note, as there is no checking in this, attempting to print a nonexistent SPR
may cause a Program exception (illegal instruction, or boundedly undefined).

Note also that this relies on the kernel text pages being writable.  If in the
future this is made not the case, this will need to be reworked.

Test Plan:
Printing the Processor Version Register (PVR, SPR 287):

db> show spr 11f
SPR 287(11f): 80240012

Differential Revision: https://reviews.freebsd.org/D7403
2016-08-13 18:46:49 +00:00
Justin Hibbits
253902b44c Add ePAPR boot support for PowerPC book-E (MPC85xx) hardware
Summary:
u-boot, following the ePAPR specification, puts secondary cores into a
spinloop at boot, rather than leaving them shut off.  It then relies on the host
OS to write the correct values to a special spin table, located in coherent
memory (on newer implementations), or noncoherent memory (older
implementations).

This supports both implementations of ePAPR, as well as continuing to support
non-ePAPR booting, by first attempting to use the spintable, and falling back to
expecting non-started CPUs.

Test Plan:
Booted on a P5020 board.  Tested before and after the changes.
Before the changes, prints the error "SMP: CPU 1 already out of hold-off state!"
and panics shortly thereafter.  After the changes, same boot method lets it
complete boot.

Reviewed by:	nwhitehorn
MFC after:	2 weeks
Relnotes:	Yes
Sponsored by:	Alex Perez/Inertial Computing
Differential Revision: https://reviews.freebsd.org/D7494
2016-08-13 16:16:02 +00:00
Justin Hibbits
d071aa6df2 Use label math instead of hard-coding offsets for return addresses.
Though the chances of the code in these sections changing are low, future-proof
the sections and use label math.

Renumber the surrounding areas to avoid duplicate label numbers.
2016-07-23 02:27:42 +00:00
Justin Hibbits
78cc33fd32 Remove booke_enable_l3_cache declaration and remaining definition.
L3 cache is not defined by Book-E, so is platform specific.  Since it was
already moved for e500-based devices into mpc85xx in r292903, just eliminate it
altogether.  Any device that supports L3 cache should have its own platform
means to enable it.
2016-07-17 19:24:28 +00:00
Justin Hibbits
b926a14ca7 No need to include mpc85xx.h anymore, so remove it. 2016-07-17 19:19:50 +00:00
Pedro F. Giffuni
910c079886 sys/powerpc: make use of the howmany() macro when available.
We have a howmany() macro in the <sys/param.h> header that is
convenient to re-use as it makes things easier to read.
2016-04-26 14:44:49 +00:00
Pedro F. Giffuni
d9c9c81c08 sys: use our roundup2/rounddown2() macros when param.h is available.
rounddown2 tends to produce longer lines than the original code
and when the code has a high indentation level it was not really
advantageous to do the replacement.

This tries to strike a balance between readability using the macros
and flexibility of having the expressions, so not everything is
converted.
2016-04-21 19:57:40 +00:00
Justin Hibbits
f60708c9f7 Fix SMP booting for PowerPC Book-E
Summary:
PowerPC Book-E SMP is currently broken for unknown reasons.  Pull in
Semihalf changes made c2012 for e500mc/e5500, which enables booting SMP.

This eliminates the shared software TLB1 table, replacing it with
tlb1_read_entry() function.

This does not yet support ePAPR SMP booting, and doesn't handle resetting CPUs
already released (ePAPR boot releases APs to a spin loop waiting on a specific
address).  This will be addressed in the near future by using the MPIC to reset
the AP into our own alternate boot address.

This does include a change to the dpaa/dtsec(4) driver, to mark the portals as
CPU-private.

Test Plan:
Tested on Amiga X5000/20 (P5020).  Boots, prints the following
messages:

 Adding CPU 0, pir=0, awake=1
 Waking up CPU 1 (dev=1)
 Adding CPU 1, pir=20, awake=1
 SMP: AP CPU #1 launched

top(1) shows CPU1 active.

Obtained from:	Semihalf
Relnotes:	Yes
Differential Revision: https://reviews.freebsd.org/D5945
2016-04-19 01:48:18 +00:00
Justin Hibbits
f00e990465 VM_MAXUSER_ADDRESS is highest page start, not highest address.
In case a single page mapping is requested first, which might overlap the user
address space, fix the device map block to the next page.
2016-04-10 15:50:45 +00:00
Justin Hibbits
f2c3b7f2ba Restructure device mappings for Book-E.
Summary:
There is currently a 1GB hole between user and kernel address spaces
into which direct (1:1 PA:VA) device mappings go.  This appears to go largely
unused, leaving all devices to contend with the 128MB block at the end of the
32-bit space (0xf8000000-0xffffffff).  This easily fills up, and needs to be
densely packed.  However, dense packing wastes precious TLB1 space, of which
there are only 16 (e500v2) or 64(e5500) entries available.

Change this by using the 1GB space for all device mappings, and allow the kernel
to use the entire upper 1GB for KVA.  This also allows us to use sparse device
mappings, freeing up TLB entries.

Test Plan: Boot tested on p5020.

Differential Revision: https://reviews.freebsd.org/D5832
2016-04-10 15:48:09 +00:00
Justin Hibbits
0aeed3e993 Add support for the Freescale dTSEC DPAA-based ethernet controller.
Freescale's QorIQ line includes a new ethernet controller, based on their
Datapath Acceleration Architecture (DPAA).  This uses a combination of a Frame
manager, Buffer manager, and Queue manager to improve performance across all
interfaces by being able to pass data directly between hardware acceleration
interfaces.

As part of this import, Freescale's Netcomm Software (ncsw) driver is imported.
This was an attempt by Freescale to create an OS-agnostic sub-driver for
managing the hardware, using shims to interface to the OS-specific APIs.  This
work was abandoned, and Freescale's primary work is in the Linux driver (dual
BSD/GPL license).  Hence, this was imported directly to sys/contrib, rather than
going through the vendor area.  Going forward, FreeBSD-specific changes may be
made to the ncsw code, diverging from the upstream in potentially incompatible
ways.  An alternative could be to import the Linux driver itself, using the
linuxKPI layer, as that would maintain parity with the vendor-maintained driver.
However, the Linux driver has not been evaluated for reliability yet, and may
have issues with the import, whereas the ncsw-based driver in this commit was
completed by Semihalf 4 years ago, and is very stable.

Other SoC modules based on DPAA, which could be added in the future:
* Security and Encryption engine (SEC4.x, SEC5.x)
* RAID engine

Additional work to be done:
* Implement polling mode
* Test vlan support
* Add support for the Pattern Matching Engine, which can do regular expression
  matching on packets.

This driver has been tested on the P5020 QorIQ SoC.  Others listed in the
dtsec(4) manual page are expected to work as the same DPAA engine is included in
all.

Obtained from:	Semihalf
Relnotes:	Yes
Sponsored by:	Alex Perez/Inertial Computing
2016-02-29 03:38:00 +00:00
Justin Hibbits
0f7aeab0e7 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
2016-02-27 20:39:36 +00:00
Justin Hibbits
debd17c5e7 Fix a panic bug that cropped up in the PTE rewrite.
PTE was getting overwritten by just the flags.

Pointy-hat to:	jhibbits
2016-02-16 02:13:55 +00:00
Justin Hibbits
64a982ea56 Migrate the PTE format for book-e to standardize on the 'indirect PTE' format
Summary:
The revised Book-E spec, adding the specification for the MMUv2 and e6500,
includes a hardware PTE layout for indirect page tables.  In order to support
this in the future, migrate the PTE format to match the MMUv2 hardware PTE
format.

Test Plan: Boot tested on a P5020 board.  Booted to multiuser mode.

Differential Revision: https://reviews.freebsd.org/D5224
2016-02-11 13:15:37 +00:00
Justin Hibbits
49d36ba409 Older Book-E processors (e500v1/e500v2) don't support dcbzl.
The only difference between dcbzl and dcbz is dcbzl operates on native cache
line lengths regardless of L1CSR0[DCBZ32].  Since we don't change the cache line
size, the cacheline_size variable will reflect the used cache line length, and
dcbz will work as expected.
2016-01-26 04:41:18 +00:00
Justin Hibbits
30857edaea Fix a debug printf().
Somehow this printf() was missed in the conversion of vm_paddr_t to 64-bit, and
made it through until now.

Sponsored by:	Alex Perez/Inertial Computing
2016-01-26 03:52:14 +00:00
Justin Hibbits
e1a51e19e0 Revert a printf change from r294307.
Caused build failures with MPC85XX.

Pointy-hat to:	jhibbits
2016-01-19 23:35:12 +00:00
Justin Hibbits
ca31148c56 Hide most of the PTE initialization and management.
By confining the page table management to a handful of functions it'll be
easier to modify the page table scheme without affecting other functions.
This will be necessary when 64-bit support is added, and page tables become
much larger.
2016-01-19 03:07:25 +00:00