Commit Graph

2897 Commits

Author SHA1 Message Date
Justin Hibbits
1a3eaf6cc8 Add an IPMI attachment for PowerNV systems
IPMI access on PowerNV systems is done through the OPAL firmware.  This adds a
simple attachment for communicating with the FSP/BMC on these machines.  This
has been tested on a Talos POWER9 workstation, only in the bootup phase, noting
the successful attachment messages:

...
ipmi0: IPMI device rev. 0, firmware rev. 2.00, version 2.0, device support mask 0
ipmi0: Number of channels 2
...

The ipmi device has not been added to GENERIC64, but may be after further
testing.  It may also eventually be added to the ipmi module at that point.
2018-05-22 03:57:32 +00:00
Justin Hibbits
5272c9bd07 Add a comment explaining the need of a global temporary variable
cpu_xirr is used only as a temporary location for the OPAL call in
PIC_DISPATCH().

Requested by:	nwhitehorn
2018-05-22 03:24:16 +00:00
Justin Hibbits
9c6ba29de1 Basic OPAL sensor support for POWER9 platforms
Summary:
PowerNV architectures (in the test case POWER9) export sensors via the device
tree, which are accessed via OPAL calls.  This adds sysctl nodes for each
device in a generic fashion.  New sysctl nodes are:

dev.opal_sensor.N.sensor
dev.opal_sensor.N.sensor_min
dev.opal_sensor.N.sensor_max
dev.opal_sensor.N.type
dev.opal_sensor.N.label

These are rooted at a parent attachment under opal, called opalsens.  This does
not add support for the "sensor groups" defined in the device tree.

Reviewed by:	breno.leitao_gmail.com
Differential Revision: https://reviews.freebsd.org/D15362
2018-05-22 02:42:53 +00:00
Nathan Whitehorn
6cff19a3be Fix build with PSERIES but not POWERNV defined. 2018-05-20 18:26:09 +00:00
Justin Hibbits
ef6da5e5c7 Add support for the XIVE XICS emulation mode for POWER9 systems
Summary:
POWER9 systems use a new interrupt controller, XIVE, managed through OPAL
firmware calls.  The OPAL firmware includes support for emulating the previous
generation XICS presentation layer in addition to a new "XIVE Exploitation"
mode.  As a stopgap until we have XIVE exploitation mode, enable XICS emulation
mode so that we at least have an interrupt controller.

Since the CPPR is local to the current CPU, it cannot be updated for APs when
initializing on the BSP.  This adds a new function, directly called by the
powernv platform code, to initialize the CPPR on AP bringup.

Reviewed by:	nwhitehorn
Differential Revision: https://reviews.freebsd.org/D15492
2018-05-20 03:23:17 +00:00
Mark Johnston
892bdccca0 Enable kernel dump features in GENERIC for most platforms.
This turns on support for kernel dump encryption and compression, and
netdump. arm and mips platforms are omitted for now, since they are more
constrained and don't benefit as much from these features.

Reviewed by:	cem, manu, rgrimes
Tested by:	manu (arm64)
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D15465
2018-05-19 19:53:23 +00:00
Justin Hibbits
4a11ed7159 Add SPR_HSRR0/SPR_HSRR1 definitions
Reported by:	Mark Millard
Pointy-hat to:	jhibbits
2018-05-19 04:56:10 +00:00
Justin Hibbits
5321c01b50 Add hypervisor trap handling, using HSRR0/HSRR1
Summary:
Some hypervisor exceptions on POWER architecture only save state to HSRR0/HSRR1.
Until we have bhyve on POWER, use a lightweight exception frontend which copies
HSRR0/HSRR1 into SRR0/SRR1, and run the normal trap handler.

The first user of this is the Hypervisor Virtualization Interrupt, which targets
the XIVE interrupt controller on POWER9.

Reviewed By: nwhitehorn
Differential Revision: https://reviews.freebsd.org/D15487
2018-05-19 04:21:50 +00:00
Justin Hibbits
30f3b0f5f7 powerpc64: Add OPAL definitions
Summary:
Add additional OPAL PCI definitions and expand the code to use them in order to
ease the OPAL interface process for new comers.

These definitions came directly from the OPAL code and they are the same for
both PHB3 (POWER8) and PHB4 (POWER9).

Submitted by:	Breno Leitao
Differential Revision: https://reviews.freebsd.org/D15432
2018-05-19 04:01:15 +00:00
Justin Hibbits
c07c77a311 Fix a manual copy from the original diff for r333825
The 'else' was in the original diff.

Submitted by:	Breno Leitao
2018-05-19 03:47:28 +00:00
Justin Hibbits
876f3b9295 Add yet another option for gathering available memory
On some POWER9 systems, 'reg' denotes the full memory in the system, while
'linux,usable-memory' denotes the usable memory.  Some memory is reserved for
NVLink usage, so is partitioned off.

Submitted by:	Breno Leitao
2018-05-19 03:45:38 +00:00
Justin Hibbits
829c98b82e Add some Hypervisor interrupt definitions
This mostly completes the interrupt definitions.  There are still some left out,
less likely to be used in the near term.
2018-05-19 03:23:46 +00:00
Matt Macy
d7c5a620e2 ifnet: Replace if_addr_lock rwlock with epoch + mutex
Run on LLNW canaries and tested by pho@

gallatin:
Using a 14-core, 28-HTT single socket E5-2697 v3 with a 40GbE MLX5
based ConnectX 4-LX NIC, I see an almost 12% improvement in received
packet rate, and a larger improvement in bytes delivered all the way
to userspace.

When the host receiving 64 streams of netperf -H $DUT -t UDP_STREAM -- -m 1,
I see, using nstat -I mce0 1 before the patch:

InMpps OMpps  InGbs  OGbs err TCP Est %CPU syscalls csw     irq GBfree
4.98   0.00   4.42   0.00 4235592     33   83.80 4720653 2149771   1235 247.32
4.73   0.00   4.20   0.00 4025260     33   82.99 4724900 2139833   1204 247.32
4.72   0.00   4.20   0.00 4035252     33   82.14 4719162 2132023   1264 247.32
4.71   0.00   4.21   0.00 4073206     33   83.68 4744973 2123317   1347 247.32
4.72   0.00   4.21   0.00 4061118     33   80.82 4713615 2188091   1490 247.32
4.72   0.00   4.21   0.00 4051675     33   85.29 4727399 2109011   1205 247.32
4.73   0.00   4.21   0.00 4039056     33   84.65 4724735 2102603   1053 247.32

After the patch

InMpps OMpps  InGbs  OGbs err TCP Est %CPU syscalls csw     irq GBfree
5.43   0.00   4.20   0.00 3313143     33   84.96 5434214 1900162   2656 245.51
5.43   0.00   4.20   0.00 3308527     33   85.24 5439695 1809382   2521 245.51
5.42   0.00   4.19   0.00 3316778     33   87.54 5416028 1805835   2256 245.51
5.42   0.00   4.19   0.00 3317673     33   90.44 5426044 1763056   2332 245.51
5.42   0.00   4.19   0.00 3314839     33   88.11 5435732 1792218   2499 245.52
5.44   0.00   4.19   0.00 3293228     33   91.84 5426301 1668597   2121 245.52

Similarly, netperf reports 230Mb/s before the patch, and 270Mb/s after the patch

Reviewed by:	gallatin
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D15366
2018-05-18 20:13:34 +00:00
Nathan Whitehorn
b00df92b1f Final fix for alignment issues with the page table first patched with
r333273 and partially reverted with r333594.

Older CPUs implement addition of offsets into the page table by a
bitwise OR rather than actual addition, which only works if the table is
aligned at a multiple of its own size (they also require it to be aligned
at a multiple of 256KB). Newer ones do not have that requirement, but it
hardly matters to enforce it anyway.

The original code was failing on newer systems with huge amounts of RAM
(> 512 GB), in which the page table was 4 GB in size. Because the
bootstrap memory allocator took its alignment parameter as an int, this
turned into a 0, removing any alignment constraint at all and making
the MMU fail. The first round of this patch (r333273) fixed this case by
aligning it at 256 KB, which broke older CPUs. Fix this instead by widening
the alignment parameter.
2018-05-14 04:00:52 +00:00
Nathan Whitehorn
b9ff14e6e9 Revert changes to hash table alignment in r333273, which booting on all G5
systems, pending further analysis.
2018-05-13 23:56:43 +00:00
Justin Hibbits
04de51dbab No need to bzero splpar_vpa entries
splpar_vpa is in the BSS, so is already zeroed when the kernel starts up.

Tested by:	Leandro Lupori
2018-05-11 02:04:01 +00:00
Justin Hibbits
b4a0a59871 Fix PPC symbol resolution
Summary:
There were 2 issues that were preventing correct symbol resolution
on PowerPC/pseries:

1- memory corruption at chrp_attach() - this caused the inital
   part of the symbol table to become zeroed, which would cause
   the kernel linker to fail to parse it.
   (this was probably zeroing out other memory parts as well)

2- DDB symbol resolution wasn't working because symtab contained
   not relocated addresses but it was given relocated offsets.
   Although relocating the symbol table fixed this, it broke the
   linker, that already handled this case.
   Thus, the fix for this consists in adding a new DDB macro:
   DB_STOFFS(offs) that converts a (potentially) relocated offset
   into one that can be compared with symbol table values.

PR:		227093
Submitted by:	Leandro Lupori <leandro.lupori_gmail.com>
Differential Revision: https://reviews.freebsd.org/D15372
2018-05-10 03:59:48 +00:00
Warner Losh
5aa07b053a Move MI-ish bcopy routine to libkern
riscv and powerpc have nearly identical bcopy.c that's
supposed to be mostly MI. Move it to the MI libkern.

Differential Revision: https://reviews.freebsd.org/D15374
2018-05-10 02:31:38 +00:00
Justin Hibbits
151c44e22b Fix wrong cpu0 identification
Summary:
chrp_cpuref_init() was relying on the boot strap processor to be
the first child of /cpus. That was not always the case, specially
on pseries with FDT.

This change uses the "reg" property of each CPU instead and also
adds several sanity checks to avoid unexpected behavior (maybe
too many panics?).

The main observed symptom was interrupts being missed by the main
processor, leading to timeouts and the kernel aborting the boot.

Submitted by:	Leandro Lupori
Reviewed by:	nwhitehorn
Differential Revision: https://reviews.freebsd.org/D15174
2018-05-08 13:23:39 +00:00
Justin Hibbits
10d0cdfc6e Add support for powernv POWER9 MMU initialization
The POWER9 MMU (PowerISA 3.0) is slightly different from current
configurations, using a partition table even for hypervisor mode, and
dropping the SDR1 register.  Key off the newly early-enabled CPU features
flags for the new architecture, and configure the MMU appropriately.

The POWER9 MMU ignores the "PSIZ" field in the PTCR, and expects a 64kB
table.  As we are enabled for powernv (hypervisor mode, no VMs), only
initialize partition table entry 0, and zero out the rest.  The actual
contents of the register are identical to SDR1 from previous architectures.

Along with this, fix a bug in the page table allocation with very large
memory.  The table can be allocated on any 256k boundary.  The
bootstrap_alloc alignment argument is an int, and with large amounts of
memory passing the size of the table as the alignment will overflow an
integer.  Hard-code the alignment at 256k as wider alignment is not
necessary.

Reviewed by:	nwhitehorn
Tested by:	Breno Leitao
Relnotes:	Yes
2018-05-05 16:00:02 +00:00
Justin Hibbits
55a12bbda2 Break out the cpu_features setup to its own function, to be run earlier
The new POWER9 MMU configuration is slightly different from current setups.
Rather than special-casing on POWER9, move the initialization of cpu_features
and cpu_features2 to as early as possible, so that platform and MMU
configuration can be based upon CPU features instead of specific CPUs if at all
possible.

Reviewed by:	nwhitehorn
2018-05-05 15:48:39 +00:00
Justin Hibbits
4f4f92c58f Add POWER9 to the POWER8 bootstrap case blocks
POWER8 and POWER9 have similar configuration requirements for hypervisor setup,
and in the cases here they're identical.  Add the POWER9 constant to the POWER8
list so it's initialized correctly.

Reviewed by:	nwhitehorn
2018-05-05 15:42:58 +00:00
Mateusz Guzik
a571c38536 Allow __builtin_memmove instead of bcopy for small buffers of known size
See r323329 for an explanation why this is a good idea.
2018-05-04 04:00:48 +00:00
Justin Hibbits
971b5e4da8 Remove dead errata fixup code
This code caused more problems than it should have fixed (boot failures) on
the machines I tested, so has been commented out for a while now.  Remove
it, and assume the errata fixups were done by the bootloader where they
belong.
2018-05-01 04:31:17 +00:00
Nathan Whitehorn
47280ef170 Fix null pointer dereference on nodes without a "compatible" property.
MFC after:	1 week
2018-04-30 19:37:32 +00:00
Justin Hibbits
42ca1d5cc3 Increase the fdtmemreserv array limit to boot on POWER9
Discussing with others, this needs to be at least 20 to boot on some POWER9
nodes.  Linux made a similar change for the same reason, so increase to 32
to give us some extra breathing room as well.  The input and output arrays
are sized at 256, so much greater than the increase in the property array
size.
2018-04-25 02:42:11 +00:00
Justin Hibbits
38c32a140b Fix the build post r332859
sysentvec::sv_hwcap/sv_hwcap2 are pointers to  u_long, so cpu_features* need
to be u_long to use the pointers.  This also requires a temporary cast in
printing the bitfields, which is fine because the feature flag fields are
only 32 bits anyway.
2018-04-22 03:58:04 +00:00
Justin Hibbits
611c02b1d2 Export powerpc CPU features for auxvec
FreeBSD exports the AT_HWCAP* auxvec items if provided by the ELF sysentvec
structure.  Add the CPU features to be exported, so user space can more
easily check for them without using the hw.cpu_features and hw.cpu_features2
sysctls.
2018-04-21 15:15:47 +00:00
Justin Hibbits
18f48e0c72 Sync powerpc feature flags with Linux
Not all feature flags are synced.  Those for processors we don't currently
support are ignored currently.  Those that are supported are synced best I
can tell.  One flag was renamed to match the Linux flag name
(PPC_FEATURE2_VCRYPTO -> PPC_FEATURE2_VEC_CRYPTO).
2018-04-21 04:18:17 +00:00
Justin Hibbits
567dd766f6 powerpc64: Set n_slbs = 32 for POWER9
Summary:
POWER9 also contains 32 slbs entries as explained by the POWER9 User Manual:

 "For HPT translation, the POWER9 core contains a unified (combined for both
   instruction and data), 32-entry, fully-associative SLB per thread"

Submitted by:	Breno Leitao
Differential Revision: https://reviews.freebsd.org/D15128
2018-04-20 03:23:19 +00:00
Justin Hibbits
2914706ab0 powerpc64: Add DSCR support
Summary:
Powerpc64 has support for a register called Data Stream Control Register
(DSCR), which basically controls how the hardware controls the caching and
prefetch for stream operations.

Since mfdscr and mtdscr are privileged instructions, we need to emulate them,
and
keep the custom DSCR configuration per thread.

The purpose of this feature is to change DSCR depending on the operation, set
to DSCR Default Prefetch Depth to deepest on string operations, as memcpy.

Submitted by:	Breno Leitao
Differential Revision: https://reviews.freebsd.org/D15081
2018-04-20 03:19:44 +00:00
Nathan Whitehorn
323e673945 Fix detection of memory overlap with the kernel in the case where a memory
region marked "available" by firmware is contained entirely in the kernel.

This had a tendency to happen with FDTs passed by loader, though could for
other reasons as well, and would result in the kernel slowly cannibalizing
itself for other purposes, eventually resulting in a crash.

A similar fix is needed for mmu_oea.c and should probably just be rolled
at that point into some generic code in platform.c for taking a mem_region
list and removing chunks.

PR:		226974
Submitted by:	leandro.lupori@gmail.com
Reviewed by:	jhibbits
Differential Revision:	D15121
2018-04-19 18:34:38 +00:00
Alexander Motin
596e6ade92 Release memory resource on cuda driver attach failure.
Submitted by:	Dmitry Luhtionov <dmitryluhtionov@gmail.com>
2018-04-19 15:29:10 +00:00
Andriy Gapon
f3f6ecb450 set kdb_why to "trap" when calling kdb_trap from trap_fatal
This will allow to hook a ddb script to "kdb.enter.trap" event.
Previously there was no specific name for this event, so it could only
be handled by either "kdb.enter.unknown" or "kdb.enter.default" hooks.
Both are very unspecific.

Having a specific event is useful because the fatal trap condition is
very similar to panic but it has an additional property that the current
stack frame is the frame where the trap occurred.  So, both a register
dump and a stack bottom dump have additional information that can help
analyze the problem.

I have added the event only on architectures that have trap_fatal()
function defined.  I haven't looked at other architectures.  Their
maintainers can add support for the event later.

Sample script:
kdb.enter.trap=bt; show reg; x/aS $rsp,20; x/agx $rsp,20

Reviewed by:	kib, jhb, markj
MFC after:	11 days
Sponsored by:	Panzura
Differential Revision: https://reviews.freebsd.org/D15093
2018-04-19 05:06:56 +00:00
Andriy Gapon
6d83b2e971 don't check for kdb reentry in trap_fatal(), it's impossible
trap() checks for it earlier and calls kdb_reentry().

Discussed with:	jhb
MFC after:	12 days
Sponsored by:	Panzura
2018-04-18 15:44:54 +00:00
Brooks Davis
9c11d8d483 Remove the unused fuwintr() and suiwintr() functions.
Half of implementations always failed (returned (-1)) and they were
previously used in only one place.

Reviewed by:	kib, andrew
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D15102
2018-04-17 18:04:28 +00:00
Warner Losh
9d89a9f326 No need to force md code to define a macro that's the same as
_BYTE_ORDER. Use that instead.
2018-04-16 13:52:23 +00:00
Justin Hibbits
3877c32ec9 Use a resource hint instead of environment variable for DIU mode
This makes it more consistent with FreeBSD norms, rather than using Linux's
norms.  Now, instead of needing an environment variable

  video-mode=fslfb:1280x1024@60

Now one would use a hint:

  hint.fb.0.mode=1280x1024@60
2018-04-16 04:02:53 +00:00
Justin Hibbits
bda8aa770a Reenter KDB on fault on powerpc, instead of panicking
Most other architectures already re-enter KDB on faults, powerpc and mips
are the only outliers.  Correct this for powerpc, so that now bad addresses
can be handled gracefully instead of panicking.
2018-04-10 21:14:54 +00:00
Justin Hibbits
99adcecf38 Call through powerpc_interrupt for all Book-E interrupts
Make int_external_input, int_decrementer, and int_performance_counter all
now use trap_common, just like on AIM.  The effects of this are:

* All traps are now properly displayed in ddb.  Previously traps from
  external input, decrementer, and performance counters, would display as
  just basic stack traces.  Now the frame is displayed.

* External interrupts are now handled with interrupts enabled, so handling
  can be preempted.  This seems to fix a hang found post-r329882.
2018-04-10 17:32:27 +00:00
Oleksandr Tymoshenko
f7604b1b27 Align OF_getencprop_alloc API with OF_getencprop and OF_getprop_alloc
Change OF_getencprop_alloc semantics to be combination of malloc and
OF_getencprop and return size of the property, not number of elements
allocated.

For the use cases where number of elements is preferred introduce
OF_getencprop_alloc_multi helper function that copies semantics
of OF_getencprop_alloc prior to this change.

This is to make OF_getencprop_alloc and OF_getencprop_alloc_multi
function signatures consistent with OF_getencprop_alloc and
OF_getencprop_alloc_multi.

Functionality-wise this patch is mostly rename of OF_getencprop_alloc
to OF_getencprop_alloc_multi except two calls in ofw_bus_setup_iinfo
where 1 was used as a block size.
2018-04-09 22:06:16 +00:00
Oleksandr Tymoshenko
217d17bcd3 Clean up OF_getprop_alloc API
OF_getprop_alloc takes element size argument and returns number of
elements in the property. There are valid use cases for such behavior
but mostly API consumers pass 1 as element size to get string
properties. What API users would expect from OF_getprop_alloc is to be
a combination of malloc + OF_getprop with the same semantic of return
value. This patch modifies API signature to match these expectations.

For the valid use cases with element size != 1 and to reduce
modification scope new OF_getprop_alloc_multi function has been
introduced that behaves the same way OF_getprop_alloc behaved prior to
this patch.

Reviewed by:	ian, manu
Differential Revision:	https://reviews.freebsd.org/D14850
2018-04-08 22:59:34 +00:00
Justin Hibbits
b4b4b17687 Fix typo
Reserved cause is 6, not 5.

Reported by:	cem
2018-04-08 19:33:05 +00:00
Justin Hibbits
ac2605b1d1 Powerpc64: Add the facility unavailable trap subsystem
Summary:
This code adds the basic infrastructure for the facility subsystem. A facility
trap is raised when an unavailable instruction is executed. One example is
executing a Hardware Transactional Memory instruction while the MSR[TM] is
disabled. In the past, there was a specific interrupt for it (FP, VEC), but the
new instructions seem to be multiplexed on this facility interrupt.

The root cause of the trap is provided on Facility Status and Control Register
(FSCR) register.

Submitted by:	Breno Leitao
Reviewed by:	nwhitehorn
Differential Revision: https://reviews.freebsd.org/D14566
2018-04-08 19:11:25 +00:00
Justin Hibbits
3762bafa7b powerpc64: Print current MSR on printtrap()
Summary:
Print current MSR on printtrap(). Currently, printtrap just prints srr1, which
contains part of the MSR prior to the exception. I find useful to dump the
current value of the MSR, since it changes when there is an interruption.

With this patch, this is the new printtrap model:

handled user trap:

    exception       = 0x700 (program)
    srr0            = 0x100008a0 (0x100008a0)
    srr1            = 0x800000000002f032
    current msr     = 0x8000000000009032
    lr              = 0x1000089c (0x1000089c)
    curthread       = 0x7a50000
	pid = 714, comm = ttrap2

Submitted by:	Breno Leitao
Reviewed by:	nwhitehorn
Differential Revision: https://reviews.freebsd.org/D14600
2018-04-08 16:55:28 +00:00
Justin Hibbits
8238d3423d powerpc64: Avoid calling isync twice
Summary:
It is not necessary to call isync() after calling mtmsr() function, mainly
because the mtmsr() calls 'isync' internally to synchronize the machine state
register. Other than that, isync() just calls the 'isync' instruction, thus,
the 'isync' instruction is being called twice, and that seems to be unnecessary.

This patch just remove the unecessary calls to isync() after mtmsr().

Submitted by:	Breno Leitao
Differential Revision: https://reviews.freebsd.org/D14583
2018-04-08 16:46:24 +00:00
Justin Hibbits
d6d0670814 powerpc/ofw: Fix malloc inside lock
Summary:
Currently ofw_real_bounce_alloc() is requesting memory, using WAITOK, holding a
non-sleepable locks, called 'OF Bounce Page'.

Fix this by allocating the pages outside of the lock, and only updating the
global variables while holding the lock.

Submitted by:	Breno Leitao
Differential Revision:	https://reviews.freebsd.org/D14955
2018-04-08 16:43:56 +00:00
Brooks Davis
6469bdcdb6 Move most of the contents of opt_compat.h to opt_global.h.
opt_compat.h is mentioned in nearly 180 files. In-progress network
driver compabibility improvements may add over 100 more so this is
closer to "just about everywhere" than "only some files" per the
guidance in sys/conf/options.

Keep COMPAT_LINUX32 in opt_compat.h as it is confined to a subset of
sys/compat/linux/*.c.  A fake _COMPAT_LINUX option ensure opt_compat.h
is created on all architectures.

Move COMPAT_LINUXKPI to opt_dontuse.h as it is only used to control the
set of compiled files.

Reviewed by:	kib, cem, jhb, jtl
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D14941
2018-04-06 17:35:35 +00:00
Justin Hibbits
9225dfbdf0 Correct the ilog2() for calculating memory sizes.
TLB1 can handle ranges up to 4GB (through e5500, larger in e6500), but
ilog2() took a unsigned int, which maxes out at 4GB-1, but truncates
silently.  Increase the input range to the largest supported, at least for
64-bit targets.  This lets the DMAP be completely mapped, instead of only
1GB blocks with it assuming being fully mapped.
2018-04-04 02:13:27 +00:00
Justin Hibbits
9f5b999aca Add support for a pmap direct map for 64-bit Book-E
As with AIM64, map the DMAP at the beginning of the fourth "quadrant" of
memory, and move the KERNBASE to the the start of KVA.

Eventually we may run the kernel out of the DMAP, but for now, continue
booting as it has been.
2018-04-03 00:45:38 +00:00