Commit Graph

3433 Commits

Author SHA1 Message Date
Vladimir Kondratyev
1975878673 hid: Import functions and constants required by new subsystem
This does an import of quirk stubs, debugging macros from USB code and
numerous usage constants used by dependent drivers.

Besides, this change renames some functions to get a better matching
with userland library and NetBSD/OpenBSD HID code. Namely:

- Old hid_report_size() renamed to hid_report_size_max()
- New hid_report_size() calculates size of given report rather than
  maximum size of all reports.
- hid_get_data_unsigned() renamed to hid_get_udata()
- hid_put_data_unsigned() renamed to hid_put_udata()

Compat shim functions are provided in usbhid.h to make possible compile
of legacy code unmodified after this change.

Reviewed by:	manu, hselasky
Differential revision:	https://reviews.freebsd.org/D27887
2021-01-08 02:18:42 +03:00
Vladimir Kondratyev
67de2db262 Factor-out hardware-independent part of USB HID support to new module
It will be used by the upcoming HID-over-i2C implementation.  Should be
no-op, except hid.ko module dependency is to be added to affected drivers.

Reviewed by:	hselasky, manu
Differential revision:	https://reviews.freebsd.org/D27867
2021-01-08 02:18:42 +03:00
Justin Hibbits
76ff03aef7 powerpc: Fix copyin/copyout race condition
It's possible for a context switch, and CPU migration, to occur between
fetching the PCPU context and extracting the pc_curpcb.  This can cause
the fault handler to be installed for the wrong thread, leading to a
panic in copyin()/copyout().  Since curthread is already in %r13, just
use that directly, as GPRs are migrated, so there is no migration race
risk.
2020-12-30 23:45:44 +01:00
Justin Hibbits
6260bfb087 powerpc: Optimize copyinstr() to avoid repeatedly mapping user strings
Currently copyinstr() uses fubyte() to read each byte from userspace.
However, this means that for each byte, it calls pmap_map_user_ptr() to
map the string into memory.  This is needlessly wasteful, since the
string will rarely ever cross a segment boundary.  Instead, map a
segment at a time, and copy as much from that segment as possible at a
time.

Measured with the HPT pmap on powerpc64, this saves roughly 8% time on
buildkernel, and 5% on buildworld, in wallclock time.
2020-12-30 23:45:35 +01:00
Justin Hibbits
adf79abc35 Radix dump updates 2020-12-30 23:45:28 +01:00
Justin Hibbits
7d7f26f5b6 powerpc/radix_mmu: Apply errata fixes for POWER9 TLB invalidation bug
Found in Linux, the only apparent source of errata documentation.
2020-12-30 23:45:21 +01:00
Justin Hibbits
ac19bf854b powerpc/aim: Add machine check handler for TLB multihit
Handle TLB multi-hit the same as ERAT multi-hit, by flushing the full
TLB.
2020-12-30 23:45:10 +01:00
Alfredo Dal'Ava Junior
6d2254bc92 [POWERPC64LE] fix sysctl dev.opal_sensor.* on little-endian kernel
- fix values returned by 'sysctls dev.opal_sensor.*.sensor'
- fix missing 'dev.opal_sensor.*.sensor_[max|min]' on sysctl

Reviewed-by: 	jhibbits
Sponsored-by:	Eldorado Research Institute (eldorado.org.br)
Differential-Revision: 	https://reviews.freebsd.org/D27365
2020-12-30 22:00:28 -03:00
Alexander V. Chernikov
d5fe384b4d Enable ROUTE_MPATH support in GENERIC kernels.
Ability to load-balance traffic over multiple path is a must-have thing for routers.
It may be used by the servers to balance outgoing traffic over multiple default gateways.

The previous implementation, RADIX_MPATH stayed in the shadow for too long.
It was not well maintained, which lead us to a vicious circle - people were using
 non-contiguous mask or firewalls to achieve similar goals. As a result, some routing
 daemons implementation still don't have multipath support enabled for FreeBSD.

Turning on ROUTE_MPATH by default would fix it. It will allow to reduce networking
 feature gap to other operating systems. Linux and OpenBSD enabled similar support
 at least 5 years ago.

ROUTE_MPATH does not consume memory unless actually used. It enables around ~1k LOC.

It does not bring any behaviour changes for userland.
Additionally, feature is (temporarily) turned off by the net.route.multipath sysctl
 defaulting to 0.

Differential Revision:	https://reviews.freebsd.org/D27428
2020-12-14 22:23:08 +00:00
Brandon Bergren
ab5711797d [PowerPC] Floating-point exception trap followup
* Fix incorrect operation on 32-bit caused by incorrectly-sized storage
  for a temporary FPSCR.
* Fix several whitespace problems.
* Don't try to enable VSX during cleanup_fpscr().

Reviewed by:	alfredo, jhibbits (earlier version)
Sponsored by:	Tag1 Consulting, Inc.
Differential Revision:	https://reviews.freebsd.org/D27453
2020-12-13 03:58:43 +00:00
Conrad Meyer
78599c32ef Add CFI start/end proc directives to arm64, i386, and ppc
Follow-up to r353959 and r368070: do the same for other architectures.

arm32 already seems to use its own .fnstart/.fnend directives, which
appear to be ARM-specific variants of the same thing.  Likewise, MIPS
uses .frame directives.

Reviewed by:	arichardson
Differential Revision:	https://reviews.freebsd.org/D27387
2020-12-05 00:33:28 +00:00
Brandon Bergren
3de50be851 [PowerPC64LE] Fix LE VSX/fpr interop
In the PCB struct, we need to match the VSX register file layout
correctly, as the VSRs shadow the FPRs.

In LE, we need to have a dword of padding before the fprs so they end up
on the correct side, as the struct may be manipulated by either the FP
routines or the VSX routines.

Additionally, when saving and restoring fprs, we need to explicitly target
the fpr union member so it gets offset correctly on LE.

Fixes weirdness with FP registers in VSX-using programs (A FPR that was
saved by the FP routines but restored by the VSX routines was becoming 0
due to being loaded to the wrong side of the VSR.)

Original patch by jhibbits.

Reviewed by:	jhibbits
Differential Revision:	https://reviews.freebsd.org/D27431
2020-12-03 01:39:59 +00:00
Konstantin Belousov
cd85379104 Make MAXPHYS tunable. Bump MAXPHYS to 1M.
Replace MAXPHYS by runtime variable maxphys. It is initialized from
MAXPHYS by default, but can be also adjusted with the tunable kern.maxphys.

Make b_pages[] array in struct buf flexible.  Size b_pages[] for buffer
cache buffers exactly to atop(maxbcachebuf) (currently it is sized to
atop(MAXPHYS)), and b_pages[] for pbufs is sized to atop(maxphys) + 1.
The +1 for pbufs allow several pbuf consumers, among them vmapbuf(),
to use unaligned buffers still sized to maxphys, esp. when such
buffers come from userspace (*).  Overall, we save significant amount
of otherwise wasted memory in b_pages[] for buffer cache buffers,
while bumping MAXPHYS to desired high value.

Eliminate all direct uses of the MAXPHYS constant in kernel and driver
sources, except a place which initialize maxphys.  Some random (and
arguably weird) uses of MAXPHYS, e.g. in linuxolator, are converted
straight.  Some drivers, which use MAXPHYS to size embeded structures,
get private MAXPHYS-like constant; their convertion is out of scope
for this work.

Changes to cam/, dev/ahci, dev/ata, dev/mpr, dev/mpt, dev/mvs,
dev/siis, where either submitted by, or based on changes by mav.

Suggested by: mav (*)
Reviewed by:	imp, mav, imp, mckusick, scottl (intermediate versions)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D27225
2020-11-28 12:12:51 +00:00
Alfredo Dal'Ava Junior
e63daed1b8 [POWERPC] print uprintf_signal 'type' field in hex
Print 'type' field in hex to improve readability

Reviewed by:	jhibbits
Differential Revision:	https://reviews.freebsd.org/D27294
2020-11-20 18:52:37 +00:00
Mark Johnston
431fb8abd7 vm_phys: Try to clean up NUMA KPIs
It can useful for code outside the VM system to look up the NUMA domain
of a page backing a virtual or physical address, specifically when
creating NUMA-aware data structures.  We have _vm_phys_domain() for
this, but the leading underscore implies that it's an internal function,
and vm_phys.h has dependencies on a number of other headers.

Rename vm_phys_domain() to vm_page_domain(), and _vm_phys_domain() to
vm_phys_domain().  Make the latter an inline function.

Add _vm_phys.h and define struct vm_phys_seg there so that it's easier
to use in other headers.  Include it from vm_page.h so that
vm_page_domain() can be defined there.

Include machine/vmparam.h from _vm_phys.h since it depends directly on
some constants defined there.

Reviewed by:	alc
Reviewed by:	dougm, kib (earlier versions)
Differential Revision:	https://reviews.freebsd.org/D27207
2020-11-19 03:59:21 +00:00
Alfredo Dal'Ava Junior
23f001f742 [POWERPC] fix signal race condition
r367416 should have called save_fpu() before kern_sigprocmask to avoid
race condition

Thanks jhibbits and bdragon for pointing it out

Reviewed by:	jhibbits
Sponsored by:	Eldorado Research Institute (eldorado.org.br)
Differential Revision:	https://reviews.freebsd.org/D27241
2020-11-17 12:33:12 +00:00
Leandro Lupori
5b58b1aaf8 [PowerPC] Don't overwrite vm.pmap sysctl node
After r367417, both mmu_oea64 and mmu_radix were defining the vm.pmap
sysctl node, resulting in the later definition hiding the properties of
the previous one. Avoid this issue by defining vm.pmap in a common
source file and declaring it where needed.

This change also standardizes the tunable name used to enable superpages
and change its default to disabled on radix MMU, because it still has some
issues with superpages.

Reviewed by:	bdragon, jhibbits
Sponsored by:	Eldorado Research Institute (eldorado.org.br)
Differential Revision:	https://reviews.freebsd.org/D27156
2020-11-17 11:36:31 +00:00
Brandon Bergren
0e0457251b [PowerPC64LE] Radix MMU fixes for LE.
There were many, many endianness fixes needed for Radix MMU. The Radix
pagetable is stored in BE (as it is read and written to by the MMU hw),
so we need to convert back and forth every time we interact with it when
running in LE.

With these changes, I can successfully boot with radix enabled on POWER9 hw.

Reviewed by:	luporl, jhibbits
Sponsored by:	Tag1 Consulting, Inc.
Differential Revision:	https://reviews.freebsd.org/D27181
2020-11-13 16:56:03 +00:00
Brandon Bergren
8801df34f0 [PowerPC] Fix powerpc64le boot after HPT superpages addition
The HPT is always stored in big-endian, as it is accessed directly by the
hardware as well as the kernel. As such, it is necessary to convert values
to and from native endian when running on LE.

Some unconverted accesses snuck in accidentally with r367417.

Apply the appropriate conversions to fix boot hanging on powerpc64le.

Sponsored by:	Tag1 Consulting, Inc.
2020-11-08 23:34:06 +00:00
Edward Tomasz Napierala
096068b976 Make powerpc use MAXARGS (defined as 8) instead of hardcoding '10'.
This brings its 'struct syscall_args' in sync with other architectures.

Reviewed by:	bdragon, jhibbits
MFC after:	2 weeks
Sponsored by:	EPSRC
Differential Revision:	https://reviews.freebsd.org/D26605
2020-11-06 19:27:27 +00:00
Leandro Lupori
8b2133d4e1 Fix powerpc and LINT builds
Fix build errors introduced by r367417 and r367390:

- Guard label reached only by powerpc64
- Guard vm_reserv_level_iffullpop call, that is not defined on powerpc
  variants that don't support superpages
- Add missing hwpmc file, for when hwpmc is built into kernel
2020-11-06 18:50:00 +00:00
Leandro Lupori
e2d6c417e3 Implement superpages for PowerPC64 (HPT)
This change adds support for transparent superpages for PowerPC64
systems using Hashed Page Tables (HPT). All pmap operations are
supported.

The changes were inspired by RISC-V implementation of superpages,
by @markj (r344106), but heavily adapted to fit PPC64 HPT architecture
and existing MMU OEA64 code.

While these changes are not better tested, superpages support is disabled by
default. To enable it, use vm.pmap.superpages_enabled=1.

In this initial implementation, when superpages are disabled, system
performance stays at the same level as without these changes. When
superpages are enabled, buildworld time increases a bit (~2%). However,
for workloads that put a heavy pressure on the TLB the performance boost
is much bigger (see HPC Challenge and pgbench on D25237).

Reviewed by:	jhibbits
Sponsored by:	Eldorado Research Institute (eldorado.org.br)
Differential Revision:	https://reviews.freebsd.org/D25237
2020-11-06 14:12:45 +00:00
Alfredo Dal'Ava Junior
5d0e861910 [POWERPC] Floating-Point Exception trap support
Add support for Floating-Point Exception traps on 32 and 64 bit platforms.
Also make sure to clean FPSCR on EXEC and thread exit

Author of initial version: Renato Riolino <renato.riolino@eldorad.org.br>

Reviewed by:	jhibbits
Sponsored by:	Eldorado Research Institute (eldorado.org.br)
Differential Revision:	https://reviews.freebsd.org/D23623
2020-11-06 13:34:30 +00:00
Leandro Lupori
6a32dae2b7 Fix powerpc and powerpcspe builds
This change fixes 32-bit PowerPC builds, that r367390 broke
(shift count >= width of type).
2020-11-05 20:18:00 +00:00
Leandro Lupori
68dd718256 [PowerPC] hwpmc: add support for POWER8/9 PMCs
This change adds support for POWER8 and POWER9 PMCs (bare metal and
pseries).
All PowerISA 2.07B non-random events are supported.

Implementation was based on that of PPC970.

Reviewed by:	jhibbits
Sponsored by:	Eldorado Research Institute (eldorado.org.br)
Differential Revision:	https://reviews.freebsd.org/D26110
2020-11-05 16:36:39 +00:00
Leandro Lupori
9fe896ec79 [PowerPC] Make PPC 970 PMC SPRs the standard ones
And add a _74XX suffix to 74XX SPRs.

This is a preparation for adding support to POWER8/9 PMCs, which have most
SPRs equal to 970 ones.

Reviewed by:	jhibbits
Sponsored by:	Eldorado Research Institute (eldorado.org.br)
Differential Revision:	https://reviews.freebsd.org/D26532
2020-11-05 14:15:50 +00:00
Alan Cox
9b4e77cb97 Tidy up the #includes. Recent changes, such as the introduction of
VM_ALLOC_WAITOK and vm_page_unwire_noq(), have eliminated the need for
many of the #includes.

Reviewed by:	kib, markj
Differential Revision:	https://reviews.freebsd.org/D27052
2020-11-02 19:20:06 +00:00
Konstantin Belousov
6f3b523c9a Avoid dump_avail[] redefinition.
Move dump_avail[] extern declaration and inlines into a new header
vm/vm_dumpset.h.  This fixes default gcc build for mips.

Reviewed by:	alc, scottph
Tested by:	kevans (previous version)
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D26741
2020-10-14 22:51:40 +00:00
Conrad Meyer
f8e8a06d23 random(4) FenestrasX: Push root seed version to arc4random(3)
Push the root seed version to userspace through the VDSO page, if
the RANDOM_FENESTRASX algorithm is enabled.  Otherwise, there is no
functional change.  The mechanism can be disabled with
debug.fxrng_vdso_enable=0.

arc4random(3) obtains a pointer to the root seed version published by
the kernel in the shared page at allocation time.  Like arc4random(9),
it maintains its own per-process copy of the seed version corresponding
to the root seed version at the time it last rekeyed.  On read requests,
the process seed version is compared with the version published in the
shared page; if they do not match, arc4random(3) reseeds from the
kernel before providing generated output.

This change does not implement the FenestrasX concept of PCPU userspace
generators seeded from a per-process base generator.  That change is
left for future discussion/work.

Reviewed by:	kib (previous version)
Approved by:	csprng (me -- only touching FXRNG here)
Differential Revision:	https://reviews.freebsd.org/D22839
2020-10-10 21:52:00 +00:00
Warner Losh
7e46dafa58 Create in-tree LINT files
Now that config(8) has supported include for 19 years, transition to
including the NOTES files. include support didn't exist at the time,
nor did the envvar stuff recently added. Now that it does, eliminate
the building of LINT files by just including everything you need.

Note: This may cause conflicts with updating in some cases.
	find sys -name LINT\* -rm
is suggested across this commit to remove the generated LINT
files.

Reviewed by: kevans
Differential Revision: https://reviews.freebsd.org/D26540
2020-10-09 01:48:14 +00:00
Alfredo Dal'Ava Junior
9470013f5a [PowerPC] add machdep.uprintf_signal sysctl
Add support for sysctl 'machdep.uprintf_signal' that prints debugging
information on trap signal.

Reviewed by:	jhibbits, luporl, bdragon
Sponsored by:	Eldorado Research Institute (eldorado.org.br)
Differential Revision:	https://reviews.freebsd.org/D26004
2020-10-08 22:00:31 +00:00
Mitchell Horne
8481aab1ac Print symbol index for unsupported relocation types
It is unlikely, but possible, that an unrecognized or unsupported
relocation type is encountered while trying to load a kernel module. If
this occurs we should offer the symbol index as a hint to the user.

While here, fix some small style issues.

Reviewed by:	markj, kib (amd64 part, in D26701)
Sponsored by:	NetApp, Inc.
Sponsored by:	Klara, Inc.
2020-10-07 18:48:10 +00:00
Emmanuel Vadot
90b8c0ea10 Fix LINT: Add backlight to NOTES 2020-10-02 20:52:09 +00:00
Edward Tomasz Napierala
1e2521ffae Get rid of sa->narg. It serves no purpose; use sa->callp->sy_narg instead.
Reviewed by:	kib
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D26458
2020-09-27 18:47:06 +00:00
Mark Johnston
78257765f2 Add a vmparam.h constant indicating pmap support for large pages.
Enable SHM_LARGEPAGE support on arm64.

Reviewed by:	alc, kib
Sponsored by:	Juniper Networks, Inc., Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D26467
2020-09-23 19:34:21 +00:00
Brandon Bergren
d20d17f6d4 [PowerPC64LE] Fix RTAS LE calls in pseries.
Similar to OPAL calls, switch to big endian to do calls to RTAS.

(Missed this one when I was doing the bulk commit of PowerPC64LE support.)

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 04:09:02 +00:00
Brandon Bergren
93a5341930 [PowerPC64LE] Fix sleeping on POWER8.
Due to enter_idle_powerx fabricating a MSR from scratch, it is necessary
for it to care about the endianness, so we don't accidentally switch
endian the first time we idle a thread.

Took about five seconds to spot after seeing an unmangled backtrace.

The hard bit was needing to temporarily set up a mutex to sort out the
logjam that happens when every thread simultaneously wakes up in the wrong
endian due to the panic IPI and panics, leaving what I can best describe as
"alphabet soup" on the console.

Luckily, I already had a patch sitting around to do that.

This brings POWER8 up to equivilence with POWER9 on PPC64LE.

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 02:28:19 +00:00
Brandon Bergren
0d356a5349 [PowerPC64LE] Fix AP spinup on powernv.
OPAL unconditionally enters secondary CPUs with only HV and SF set.

I tried writing a secondary entry point instead, but OPAL rejected it
and I am unsure why, so I resorted to making the system reset interrupt
endian-flexible.

This means we take a slight performance hit on wakeup on LE, but it is
a good stopgap until we can figure out a reliable way to make OPAL enter
where we want it to.

It probably makes sense to have it around anyway, because I can imagine
scenarios where the cpu resets itself to BE and does a software reset.

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 01:56:26 +00:00
Brandon Bergren
05c3051f86 [PowerPC64LE] Endian fix for opal_hmi.c
Another boring one. We need to endian swap before checking flags.

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 01:51:01 +00:00
Brandon Bergren
f9acb7a818 [PowerPC64LE] Get XIVE up and running.
More endian conversion.

* Install TCEs correctly (i.e. in big endian)

* Convert to big endian and back when setting up queue pages and IRQs.

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 01:49:37 +00:00
Brandon Bergren
bf933a83ec [PowerPC64LE] Endian fix for opal_dev.c.
Not much to say here, another missing be64toh() in memory that was written
from OPAL.

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 01:41:51 +00:00
Brandon Bergren
9cbcb6ffce [PowerPC64LE] Endian fixes for opal_pci.c.
Since OPAL runs in big endian, any data being passed back and forth
via memory instead of registers needs to be byteswapped.

From my notes during development:

"A good way to find candidates is to look for vtophys() in opal_call()
parameters. The memory being passed will be written into in BE."

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 01:37:01 +00:00
Brandon Bergren
d418d3f616 [PowerPC64LE] Implement endian-independent dword atomic PTE lock.
It's much easier to implement this in an endian-independent way when we
don't also have to worry about masking half of the dword off.

Given that this code ran on a machine that ran a poudriere bulk with no
kernel oddities, I am relatively certain it is correctly implemented. ;)

This should be a minor performance boost on BE as well.

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 01:33:54 +00:00
Brandon Bergren
f475e00fb3 [PowerPC64LE] Fix endian conversion bugs in moea64.
For a body of code that had its endian conversion bits written blind without
the ability to test, moea64 was VERY close to being correct.

There were only four instances where the existing code was getting it wrong.

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 01:29:33 +00:00
Brandon Bergren
6e5dbfb2bf [PowerPC64LE] Initial GENERIC64LE kernel config.
This is slightly stripped down from GENERIC64, as PowerMac G5 machines
are incapable of running in LE mode (so we can skip the Mac drivers.)

While technically POWER6 and POWER7 have the hardware capability of running
in LE mode, they have a tendency to trap excessively when a load/store is
misaligned. (an extremely common occurrence in LE code, and one of the main
reasons I consider BE to be superior, as it turns potential security issues
into immediately obvious mangled numbers.)

Additionally, there was no mechanism to control what endian interrupts
are delivered in, so supporting LE operation on POWER6 and POWER7 involves
some really dirty tricks in the interrupt vectors that I would rather
avoid.

IBM drew the line in the sand at POWER8 some time around 2013, embracing
full support for LE in the platform, and making a push across the board
for LE code to target POWER8 as a minimum requirement. As such, usage of
LE kernels on POWER6 and POWER7 is practically nil, despite it being
technically possible to do.

The so-called "TRUELE" feature bit which is the baseline requirement for
 needed for PowerPC64LE was introduced in POWER8.

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 01:07:55 +00:00
Brandon Bergren
c16359cf66 [PowerPC64LE] powernv ILE setup code.
When running without a hypervisor, we need to set the ILE bit in the LPCR
ourselves.

For the boot processor, handle it in powernv_attach() like we do for other
LPCR bits.

No change for the APs, as they will use the lpcr global to set up their own
LPCR when they do their own cpudep_ap_early_bootstrap() and pick up this
automatically.

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 00:32:50 +00:00
Brandon Bergren
dadfbc2e60 [PowerPC64LE] LE opal_call() implementation
OPAL runs in big endian, so we need to rfid into it to switch endian
atomically when branching to it, and we need to do the
RETURN_TO_NATIVE_ENDIAN dance when it returns to us.

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 00:28:47 +00:00
Brandon Bergren
c0290b3de8 [PowerPC64LE] Fix endianness issues in phyp_vscsi.
Unlike virtio, which in legacy mode is guest endian, the hypervisor vscsi
interface operates in big endian, so we must convert back and forth in several
places.

These changes are enough to attach a rootdisk.

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 00:13:58 +00:00
Brandon Bergren
4efb1ca7d2 [PowerPC64LE] Work around qemu TCG bug in mtmsrd emulation.
The TCG implementation of mtmsrd in qemu blindly copies the entire register
to the MSR, instead of the specific bit positions listed in the ISA.

This means that qemu will prematurely switch endian out from under the
running code instead of waiting for the rfid, causing an immediate trap
as it attempts to interpret the next instruction in the wrong endianness.

To work around this, ensure PSL_LE is still set before doing the mtmsrd.

In the future, we may wish to just turn off translation and unconditionally
use rfid to switch to the ofmsr instead of quasi-switching to the ofmsr.

Add a new platform option so this can be disabled. (And so that we can
conditonalize additional QEMU-specific hacks in the platform code.)

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 00:09:29 +00:00
Brandon Bergren
15be37cb7f [PowerPC64LE] Fix endianness issues in phyp and opal consoles.
This applies to both pseries and powernv, which were tested at different
points during the patchset development.

Sponsored by:	Tag1 Consulting, Inc.
2020-09-23 00:06:48 +00:00