Summary:
Instead of searching for a PVO entry before adding, take advantage of
the fact that RB_INSERT() returns NULL if it inserts, and the existing entry if
an entry exists, without inserting a new entry. This saves an extra tree
traversal in the cases where the PVO does not exist.
Reviewed by: luporl
Differential Revision: https://reviews.freebsd.org/D20944
EFSCFD (floating point single convert from double) emulation requires saving
the high word of the register, which uses SPE instructions. Enable the SPE
to avoid an SPV Unavailable exception.
MFC after: 1 week
'=' asm constraint marks a variable as write-only. Because of this, gcc
throws away the initialization of 'res', causing garbage to be returned if
the CAS was successful. Use '+' to mark res as read/write, so that the
initialization stays in the generated asm. Also, fix the reservation
clearing stwcx store index register in casueword32, and only do the dummy
store when needed, skip it if the real store has already succeeded.
syscallret() doesn't use error anymore. Fix a few other places to permit
removing the return value from syscallenter() entirely.
- Remove a duplicated assertion from arm's syscall().
- Use td_errno for amd64_syscall_ret_flush_l1d.
Reviewed by: kib
MFC after: 1 month
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D2090
The only consumer of moea64_pvo_remove_from_page_locked() already has the
page in hand, so there is no need to search for the page while holding the
lock. Drop the wrapper, and rename _moea64_pvo_remove_from_page_locked().
Reported by: alc
Summary:
Since the 'page pv' lock is one of the most highly contended locks, we
need to try to do as much work outside of the lock as we can. The
moea64_pvo_remove_from_page() path is a low hanging fruit, where we can
do some heavy work (PHYS_TO_VM_PAGE()) outside of the lock if needed.
In one path, moea64_remove_all(), the PV lock is already held and can't
be swizzled, so we provide two ways to perform the locked operation, one
that can call PHYS_TO_VM_PAGE outside the lock, and one that calls with
the lock already held.
Reviewed By: luporl
Differential Revision: https://reviews.freebsd.org/D20694
Summary:
If an illegal instruction is encountered on a process running on a
powerpc64 kernel it would attempt to sync the cache before retrying the
instruction "just in case". However, since curpmap is not set, when
moea64_sync_icache() attempts to lock the pmap, it's locking on a NULL pointer,
triggering a panic. Fix this by adding a (assumed unnecessary) fallback to
curthread's pmap in moea64_sync_icache().
Reported by: alfredo.junior_eldorado.org.br
Reviewed by: luporl, alfredo.junior_eldorado.org.br
Differential Revision: https://reviews.freebsd.org/D20911
Casueword(9) on ll/sc architectures must be prepared for userspace
constantly modifying the same cache line as containing the CAS word,
and not loop infinitely. Otherwise, rogue userspace livelocks the
kernel.
To fix the issue, change casueword(9) interface to return new value 1
indicating that either comparision or store failed, instead of relying
on the oldval == *oldvalp comparison. The primitive no longer retries
the operation if it failed spuriously. Modify callers of
casueword(9), all in kern_umtx.c, to handle retries, and react to
stops and requests to terminate between retries.
On x86, despite cmpxchg should not return spurious failures, we can
take advantage of the new interface and just return PSL.ZF.
Reviewed by: andrew (arm64, previous version), markj
Tested by: pho
Reported by: https://xenbits.xen.org/xsa/advisory-295.txt
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D20772
Summary:
Running a 32-bit process on a 64-bit POWER CPU may still use all 64-bits
in calculations, while ignoring the upper 32 bits for addressing
storage. It so happens that some processes end up with r1 (SP) having
bit 31 set in some cases (33-bit address). Writing out to this 33-bit
address obviosly fails. Since the CPU ignores the upper bits, we should
as well.
sendsig() and cpu_fetch_syscall_args() appear to be the only functions
that actually rely on userspace register values for copy in/out, and
cpu_fetch_syscall_args() doesn't seem to be bitten in practice yet.
Reviewed By: luporl
Differential Revision: https://reviews.freebsd.org/D20896
On POWER9/pseries, QEMU passes several regions of memory,
instead of a single region containing all memory, as the
code was expecting.
Reviewed by: jhibbits
Differential Revision: https://reviews.freebsd.org/D20857
sv_maxuser specifies the maximum addressable space for user space. Presently
this is all 64-bits worth, which is impossible for a 32-bit process.
This bug has existed since the initial import of powerpc64 in 2010.
MFC after: 2 weeks
The hold_count and wire_count fields of struct vm_page are separate
reference counters with similar semantics. The remaining essential
differences are that holds are not counted as a reference with respect
to LRU, and holds have an implicit free-on-last unhold semantic whereas
vm_page_unwire() callers must explicitly determine whether to free the
page once the last reference to the page is released.
This change removes the KPIs which directly manipulate hold_count.
Functions such as vm_fault_quick_hold_pages() now return wired pages
instead. Since r328977 the overhead of maintaining LRU for wired pages
is lower, and in many cases vm_fault_quick_hold_pages() callers would
swap holds for wirings on the returned pages anyway, so with this change
we remove a number of page lock acquisitions.
No functional change is intended. __FreeBSD_version is bumped.
Reviewed by: alc, kib
Discussed with: jeff
Discussed with: jhb, np (cxgbe)
Tested by: pho (previous version)
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D19247
Although PPC SLB code doesn't handle allocation failures,
which are rare, in most places it asserts that the pointer
returned by uma_zalloc() is not NULL, making it easier to
identify the failure and avoiding an invalid pointer dereference.
This change simply adds a missing KASSERT in SLB code.
There was an issue in pseries llan driver, that resulted in the first 2 bytes
of the MAC address getting stripped, and the last 2 being always 0.
In most cases the network interface still worked, despite the MAC being
different of what was specified to QEMU, but when some other host or DHCP
server expected a specific MAC, this would fail.
This change fixes this by shifting right by 2 the local-mac-address read from
device tree, if its length is 6 instead of 8, as observed in QEMU DT, that
always presents a 6 bytes value for this property.
PR: 237471
Reported by: Alfredo Dal'Ava Junior
Reviewed by: jhibbits
Differential Revision: https://reviews.freebsd.org/D20843
Misaligned floating point loads and stores are already handled for AIM, but
use the DSISR to obtain the necessary data. Book-E does not have the DSISR,
so these fixups are not performed, leading to a SIGBUS on misaligned FP
loads or stores. Obtain the necessary data on the Book-E side, similar to
how is done for SPE.
MFC after: 1 week
Summary:
PowerPC has two PLT models: BSS-PLT and Secure-PLT. BSS-PLT uses runtime
code generation to generate the PLT stubs. Secure-PLT was introduced with
GCC 4.1 and Binutils 2.17 (base has GCC 4.2.1 and Binutils 2.17), and is a
more secure PLT format, using a read-only linkage table, with the dynamic
linker populating a non-executable index table.
This is the libc, rtld, and kernel support only. The toolchain and build
parts will be updated separately.
Reviewed By: nwhitehorn, bdragon, pfg
Differential Revision: https://reviews.freebsd.org/D20598
MFC after: 1 month
r348783 changed the behavior of the kernel mappings and broke booting on G5.
- Split the kernel mapping logic out so that the case where we are
running from the wrong memory space is handled using identity
mappings, and the case where we are not using a DMAP is handled by
forcibly mapping the kernel into the dmap range as intended by
r348783.
Reported by: Mikael Urankar
Reviewed by: luporl
Approved by: jhibbits (mentor)
Differential Revision: https://reviews.freebsd.org/D20608
When building a kernel supporting PSERIES but not POWERNV,
the compiler would complain about an error variable being
possibly used before being initialized.
In practice, however, this should never happen. In any case, it
is now initialized to an error value.
Before this change, OFW initrd (as md) handling code was simulating an ofwbus
device. But as there isn't really a Device Tree (DT) node representing OFW
initrd (it is specified in 2 properties under /chosen), its driver was in fact
stealing other driver's DT node. This was noticed after MD_ROOT_MEM became
default and QEMU's USB keyboard stopped working under VNC.
This change consists in simplifying the process of detection and mapping of
initrd memory, turning it into a simple startup step, instead of trying to
simulate a device.
Reviewed by: jhibbits
Differential Revision: https://reviews.freebsd.org/D20553
When an HMI occurs a message event also gets created with the details of the
exception. Hook into the messaging framework to retrieve the HMI message.
Nothing is done with it yet, except to panic on unhandled exception.
vmem_xalloc() cannot be called while holding a nonblocking mutex, warned
by WITNESS. The lock may not be necessary in general, but it avoids
superfluous concurrent OPAL calls for the same sensor.
Reported by: pkubaj
This set of changes make it possible to run FreeBSD for PowerPC64/pseries,
under QEMU/KVM, without requiring the host to make hugepages available to the
guest.
While there was already this possibility, by means of setting hw_direct_map to
0, on PowerPC64 there were a couple of issues/wrong assumptions that prevented
this from working, before this changelist.
Reviewed by: jhibbits
Differential Revision: https://reviews.freebsd.org/D20522
Summary:
moea64_insert_pteg_native()'s invalidation only works by happenstance.
The purpose of the shifts and XORs is to extract the VSID in order to
reverse-engineer the lower bits of the VPN. Currently a segment size is 256MB
(2**28), and ADDR_API_SHFT64 is 16, so ADDR_PIDX_SHIFT is equivalent. However,
it's semantically incorrect, in that we don't want to shift by the page shift
size, we want to shift to get to the VSID.
Tested by: bdragon
Differential Revision: https://reviews.freebsd.org/D20467
Having this option enabled by default on PowerPC64 kernels makes
booting ISO images much easier when on PowerNV.
With it, the ISO may simply be given to the -i flag of kexec.
Better yet, the ISO may be loop mounted on PetitBoot and its
kernel may be used to load itself.
Without this option, booting ISOs on remote PPC64 machines usually
involve preparing a separate kernel, with this option enabled.
DBCR0, according to the Freescale EREF, is guaranteed to be updated, and
changes take effect, after an isync plus change of MSR[DE] from 0 to 1.
Otherwise it's guaranteed to be updated "eventually". Use the expected
synchronization sequence to write it for resetting.
This prevents "Reset failed" from being printed immediately before the CPU
resets.
MFC after: 2 weeks
Actually set the source and destination VA's before using them. Fixes a
bizarre panic on 32-bit Book-E. Not sure why this wasn't caught by the
compiler.
The MSR[EE] bit does not require synchronization when changing. This is a
trivial micro-optimization, removing the trailing isync from mtmsr().
MFC after: 1 week
This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h"
in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header
pollution substantially.
EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c
files into appropriate headers (e.g., sys/proc.h, powernv/opal.h).
As a side effect of reduced header pollution, many .c files and headers no
longer contain needed definitions. The remainder of the patch addresses
adding appropriate includes to fix those files.
LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by
sys/mutex.h since r326106 (but silently protected by header pollution prior
to this change).
No functional change (intended). Of course, any out of tree modules that
relied on header pollution for sys/eventhandler.h, sys/lock.h, or
sys/mutex.h inclusion need to be fixed. __FreeBSD_version has been bumped.
It was found during building llvm that the page pv lock pool was seeing very
high contention. Since the pmap is already NUMA aware, it was surmised that
the domains were referencing similar pages in the different domains. This
reduces contention to the point of noise in a lockstat(8) run (~51% down to
under 5%), reducing build times by up to 20%.
This doesn't do a perfect domain alignment, just a best-guess based on
hardware available, that the domain is roughly specified in the upper bits
of the PA. Trying to be more clever would more than likely result in
reduced performance just on the work needed.
MFC after: 2 weeks
Since we now have a much larger KVA on powerpc64, it's possible to get SLB
traps earlier in boot, possibly even before the HIOR is properly configured
for us. Move the HIOR setup to immediately after reset, so that we use our
exception handlers instead of Open Firmware's.
PR: 233863
Submitted by: Mark Millard (partial)
Reported by: Mark Millard
MFC after: 2 weeks
Having IPSEC compiled into the kernel imposes a non-trivial
performance penalty on multi-threaded workloads due to IPSEC
refcounting. In my benchmarks of multi-threaded UDP
transmit (connected sockets), I've seen a roughly 20% performance
penalty when the IPSEC option is included in the kernel (16.8Mpps
vs 13.8Mpps with 32 senders on a 14 core / 28 HTT Xeon
2697v3)). This is largely due to key_addref() incrementing and
decrementing an atomic reference count on the default
policy. This cause all CPUs to stall on the same cacheline, as it
bounces between different CPUs.
Given that relatively few users use ipsec, and that it can be
loaded as a module, it seems reasonable to ask those users to
load the ipsec module so as to avoid imposing this penalty on the
GENERIC kernel. Its my hope that this will make FreeBSD look
better in "out of the box" benchmark comparisons with other
operating systems.
Many thanks to ae for fixing auto-loading of ipsec.ko when
ifconfig tries to configure ipsec, and to cy for volunteering
to ensure the the racoon ports will load the ipsec.ko module
Reviewed by: cem, cy, delphij, gnn, jhb, jpaetzel
Differential Revision: https://reviews.freebsd.org/D20163
* Make mmu_booke_sync_icache() use the DMAP on 64-bit prcoesses, no need to
map the page into the user's address space. This removes the
pvh_global_lock from the equation on 64-bit.
* Don't map the page with user-readability on 32-bit. I don't know what the
chance of a given user process being able to access the NULL page when
another process's page is added there, but it doesn't seem like a good
idea to map it to NULL with user read permissions.
* Only sync as much as we need to. There are only two significant places
where pmap_sync_icache is used: proc_rwmem(), and the SIGILL second-chance
for powerpc. The SIGILL second chance is likely the most common, and only
syncs 4 bytes, so avoid the other 127 loop iterations (4096 / 32 byte
cacheline) in __syncicache().
Reduce the surface area of the TLB locks. Unfortunately the same trick for
serializing the tlbie instruction on OEA64 cannot be used here to reduce the
scope of the tlbivax mutex to the tlbsync only, as the mutex also serializes
the TLB miss lock as a side effect, so contention on this lock may not be
reducible any further.
tun(4) and tap(4) share the same general management interface and have a lot
in common. Bugs exist in tap(4) that have been fixed in tun(4), and
vice-versa. Let's reduce the maintenance requirements by merging them
together and using flags to differentiate between the three interface types
(tun, tap, vmnet).
This fixes a couple of tap(4)/vmnet(4) issues right out of the gate:
- tap devices may no longer be destroyed while they're open [0]
- VIMAGE issues already addressed in tun by kp
[0] emaste had removed an easy-panic-button in r240938 due to devdrn
blocking. A naive glance over this leads me to believe that this isn't quite
complete -- destroy_devl will only block while executing d_* functions, but
doesn't block the device from being destroyed while a process has it open.
The latter is the intent of the condvar in tun, so this is "fixed" (for
certain definitions of the word -- it wasn't really broken in tap, it just
wasn't quite ideal).
ifconfig(8) also grew the ability to map an interface name to a kld, so
that `ifconfig {tun,tap}0` can continue to autoload the correct module, and
`ifconfig vmnet0 create` will now autoload the correct module. This is a
low overhead addition.
(MFC commentary)
This may get MFC'd if many bugs in tun(4)/tap(4) are discovered after this,
and how critical they are. Changes after this are likely easily MFC'd
without taking this merge, but the merge will be easier.
I have no plans to do this MFC as of now.
Reviewed by: bcr (manpages), tuexen (testing, syzkaller/packetdrill)
Input also from: melifaro
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D20044
Since the DMAP is only available on powerpc64, and is *always* available on
Book-E powerpc64, don't penalize either side (32-bit or 64-bit) by always
checking hw_direct_map to perform operations. This saves 5-10% time on
various ports builds, and on buildworld+buildkernel on Book-E hardware.
MFC after: 3 weeks
Use the nitems() macro instead of the expansion, a'la r298352. Also, fix the
location of this check to after initializing availmem_regions_sz, so that the
check isn't always against 0, thus always failing (nitems(phys_avail) is always
more than 0).
Summary:
A few ports fail to build due to missing pmap-related definitions, which are
specific per-pmap type. This tries to appease those ports, by merging all
pmaps together.
A future change will move the inline page directory out of the Book-E pmap,
to eliminate the last #ifdefs in pmap.h and complete the merge.
Reviewed By: luporl
Differential Revision: https://reviews.freebsd.org/D20119
