In particular, restart should be only done when the failure is
transient. For this, recheck the count1 value after the operation.
Note that do_sem_wait() is older usem interface.
Reported and tested by: bdrewery
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
This allows to simulated disk that is responding slowly to the IO requests.
Reviewed by: markj, bcr, pjd (previous version)
Differential Revision: https://reviews.freebsd.org/D21052
Avoid potential structure padding leak. r350294 identified a leak via
static analysis; although there's no report of a leak with the
DIOCGETSRCNODES ioctl it's a good practice to zero the memory.
Suggested by: kp
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
The motivation for this change is to allow wrappers around shm to be written
that don't set CLOEXEC. kern_shm_open currently accepts O_CLOEXEC but sets
it unconditionally. kern_shm_open is used by the shm_open(2) syscall, which
is mandated by POSIX to set CLOEXEC, and CloudABI's sys_fd_create1().
Presumably O_CLOEXEC is intended in the latter caller, but it's unclear from
the context.
sys_shm_open() now unconditionally sets O_CLOEXEC to meet POSIX
requirements, and a comment has been dropped in to kern_fd_open() to explain
the situation and add a pointer to where O_CLOEXEC setting is maintained for
shm_open(2) correctness. CloudABI's sys_fd_create1() also unconditionally
sets O_CLOEXEC to match previous behavior.
This also has the side-effect of making flags correctly reflect the
O_CLOEXEC status on this fd for the rest of kern_shm_open(), but a
glance-over leads me to believe that it didn't really matter.
Reviewed by: kib, markj
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D21119
mapping and then destroy one of the 4 KB page mappings so that there is a
potential trigger for repromotion. Currently, we destroy the first 4 KB
page mapping that falls within the (current) superpage mapping or the
virtual address range [sva, eva). However, I have found empirically that
destroying the last 4 KB mapping produces slightly better results,
specifically, more promotions and fewer failed promotion attempts.
Accordingly, this revision changes pmap_advise() to destroy the last 4 KB
page mapping. It also replaces some nearby uses of boolean_t with bool.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D21115
It is assembled using "${CC} -x assembler-with-cpp", which by convention
(bsd.suffixes.mk) uses the .asm extension.
This is a portion of the review referenced below (D18344). That review
also renamed linux_support.s to .S, but that is a functional change
(using the compiler's integrated assembler instead of as) and will be
revisited separately.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18344
witness has long had a facility to "bless" designated lock pairs. Lock
order reversals between a pair of blessed locks are not reported upon.
We have a number of long-standing false positive LOR reports; start
marking well-understood LORs as blessed.
This change hides reports about UFS vnode locks and the UFS dirhash
lock, and UFS vnode locks and buffer locks, since those are the two that
I observe most often. In the long term it would be preferable to be
able to limit blessings to a specific site where a lock is acquired,
and/or extend witness to understand why some lock order reversals are
valid (for example, if code paths with conflicting lock orders are
serialized by a third lock), but in the meantime the false positives
frequently confuse users and generate bug reports.
Reviewed by: cem, kib, mckusick
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21039
copy_file_range() operates on a pair of file descriptors; it requires
CAP_READ for the source descriptor and CAP_WRITE for the destination
descriptor.
Reviewed by: kevans, oshogbo
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21113
Attempt to mitigate the security risks around refcount overflows by
introducing a "saturated" state for the counter. Once a counter reaches
INT_MAX+1, subsequent acquire and release operations will blindly set
the counter value to INT_MAX + INT_MAX/2, ensuring that the protected
resource will not be freed; instead, it will merely be leaked.
The approach introduces a small race: if a refcount value reaches
INT_MAX+1, a subsequent release will cause the releasing thread to set
the counter to the saturation value after performing the decrement. If
in the intervening window INT_MAX refcount releases are performed by a
different thread, a use-after-free is possible. This is very difficult
to trigger in practice, and any situation where it could be triggered
would likely be vulnerable to reference count wraparound problems
to begin with. An alternative would be to use atomic_cmpset to acquire
and release references, but this would introduce a larger performance
penalty, particularly when the counter is contended.
Note that refcount_acquire_checked(9) maintains its previous behaviour;
code which must accurately track references should use it instead of
refcount_acquire(9).
Reviewed by: kib, mjg
MFC after: 3 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21089
The current implementation of gzipped a.out support was based
on a very old version of InfoZIP which ships with an ancient
modified version of zlib, and was removed from the GENERIC
kernel in 1999 when we moved to an ELF world.
PR: 205822
Reviewed by: imp, kib, emaste, Yoshihiro Ota <ota at j.email.ne.jp>
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D21099
Both of these functions atomically unwire a page, optionally attempt
to free the page, and enqueue or requeue the page. Add functions
vm_page_release() and vm_page_release_locked() to perform the same task.
The latter must be called with the page's object lock held.
As a side effect of this refactoring, the buffer cache will no longer
attempt to free mapped pages when completing direct I/O. This is
consistent with the handling of pages by sendfile(SF_NOCACHE).
Reviewed by: alc, kib
MFC after: 2 weeks
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D20986
If we take a WnR permission fault on a managed, writeable and dirty
PTE, simply return success without calling the main fault handler. This
situation can occur if multiple threads simultaneously access a clean
writeable mapping and trigger WnR faults; losers of the race to mark the
PTE dirty would end up calling the main fault handler, which had no work
to do.
Reported by: alc
Reviewed by: alc
MFC with: r350004
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21097
This is a partial merge of 350144 from projects/fuse2
PR: 236466
Reviewed by: markj
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21095
Terasic DE10-Pro (an Intel Stratix 10 GX/SX FPGA Development Kit).
The Altera EMAC is an instance of Synopsys DesignWare Gigabit MAC.
This driver sets correct clock range for MDIO interface on Intel Stratix 10
platform.
This is required due to lack of support for clock manager device for
this platform that could tell us the clock frequency value for ethernet
clock domain.
Sponsored by: DARPA, AFRL
ACTION_PTR() returns pointer to the start of rule action section,
but rule can keep several rule modifiers like O_LOG, O_TAG and O_ALTQ,
and only then real action opcode is stored.
ipfw_get_action() function inspects the rule action section, skips
all modifiers and returns action opcode.
Use this function in ipfw_reset_eaction() and flush_nat_ptrs().
MFC after: 1 week
Sponsored by: Yandex LLC
r343275 introduced a performance optimisation to the copyin/copyout
routines by attempting to copy word-per-word rather than byte-per-byte
where possible.
This optimisation failed to account for cases where the buffer is longer
than XLEN_BYTES, but due to misalignment does not not allow for any
word-sized copies. E.g. a 9 byte buffer (with XLEN_BYTES == 8) which is
misaligned by 2 bytes. The code nevertheless did a single full-word
copy, which meant we copied too much data. This potentially clobbered
other data.
This is most easily demonstrated by a simple `sysctl -a`.
Fix it by not assuming that we'll always have at least one full-word
copy to do, but instead checking the remaining length first.
Reviewed by: markj@, mhorne@, br@ (previous version)
MFC after: 1 week
Sponsored by: Axiado
Differential Revision: https://reviews.freebsd.org/D21100
Remove our (very partial) support for RFC2675 Jumbograms. They're not
used, not actually supported and not a good idea.
Reviewed by: thj@
Differential Revision: https://reviews.freebsd.org/D21086
After r343619 ipfw uses own locking for packets flow. PULLUP_LEN() macro
is used in ipfw_chk() to make m_pullup(). When m_pullup() fails, it just
returns via `goto pullup_failed`. There are two places where PULLUP_LEN()
is called with IPFW_PF_RLOCK() held.
Add PULLUP_LEN_LOCKED() macro to use in these places to be able release
the lock, when m_pullup() fails.
Sponsored by: Yandex LLC
Since DTS from >= Linux 5.0 the slave address are relative to the parent
node address and aren't the full ones.
Check both so the cpsw driver can find the phy id.
r350229 changed the code to lookup the ti,hwmods property in the parent
as it's now like that in the DTS from >= Linux 5.0, allow the property
to be also in the node itself so we can boot with an older DTB.
Reported by: "Dr. Rolf Jansen" <rj@obsigna.com>
DCTCP specific methods. Also fallthrough NewReno for non ECN capable
TCP connections and improve the integer arithmetic.
Obtained from: Richard Scheffenegger
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D20550
* Initialize the alpha parameter to a conservative value (like Linux)
* Improve handling of arithmetic.
* Improve man-page
Obtained from: Richard Scheffenegger
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D20549
counter, and the final freeing of freed swap blocks, outside the
region where an object lock is held. Correct some style(9) and
spelling errors. Change a panic() to a KASSERT(). Change a boolean_t
to a bool.
Suggested by: alc
Reviewed by: alc
Approved by: kib, markj (mentors)
Differential Revision: https://reviews.freebsd.org/D21093
v_inval_buf_range invalidates all buffers within a certain LBA range of a
file. It will be used by fusefs(5). This commit is a partial merge of
r346162, r346606, and r346756 from projects/fuse2.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21032
If not limited by write_same_max_lba option, split operation into several
2^^31 blocks chunks in a loop. For large disks it may take a while, so
setting write_same_max_lba may be useful to avoid timeouts.
While there, fix build with CAM_CTL_DEBUG.
MFC after: 2 weeks
Nothing uses these anymore. They were for super small armv4 boards without
uboot. We removed armv4 support before 13.0, but neglected to garbage collect
this at the same time. Today, both flavors of armv5 kernels (mv and ralink) boot
via uboot which has its own compression scheme for boards that need it.
Note: OLDFILES has not been updated beacuse installkernel will move the whole
directory out of the way before installing the new kernel.
Differential Revision: https://reviews.freebsd.org/D21072
Substitute driver-defined IS_P2ALIGNED() with EFX_IS_P2ALIGNED()
defined in libefx.
Add type argument and cast value and alignment to one specified type.
Reported by: Andrea Valsania <andrea.valsania at answervad.it>
Reviewed by: philip
Sponsored by: Solarflare Communications, Inc.
MFC after: 2 days
Differential Revision: https://reviews.freebsd.org/D21076
Substitute driver-defined P2ALIGN() with EFX_P2ALIGN() defined in
libefx.
Cast value and alignment to one specified type to guarantee result
correctness.
Reported by: Andrea Valsania <andrea.valsania at answervad.it>
Reviewed by: philip
Sponsored by: Solarflare Communications, Inc.
MFC after: 2 days
Differential Revision: https://reviews.freebsd.org/D21075
Substitute driver-defined P2ROUNDUP() h with EFX_P2ROUNDUP()
defined in libefx.
Cast value and alignment to one specified type to guarantee result
correctness.
Reported by: Andrea Valsania <andrea.valsania at answervad.it>
Reviewed by: philip
Sponsored by: Solarflare Communications, Inc.
MFC after: 2 days
Differential Revision: https://reviews.freebsd.org/D21074
r346932 replaced a call to vn_bmap_seekhole() with a call to
ufs_bmap_seekdata(). Although vn_bmap_seekhole() locks the vnode,
ufs_bmap_seekdata() assumes it is already locked.
This patch adds locking of the vnode before the ufs_bmap_seekdata() call.
If the vn_lock() call fails, it returns EBADF since that is the normal
error returned when a file system is forced dismounted and is already
listed as an error return in the lseek(2) man page.
Discussed with: markj
Reviewed by: kib
We want to allocate a contiguous memory block anywhere in memory, but
expressed this as having to be between 0 and 0xffffffff. This limits us
on 64-bit machines, and outright breaks on machines where memory is
mapped above that address range.
Allow the full address range to be used for this allocation.
Sponsored by: Axiado
The values to report can be set via LUN options. It can be useful for
testing, and also required for Drive Maintenance 2016 feature set.
MFC after: 2 weeks
CTL implements all defined feature sets except Drive Maintenance 2016,
which is not very applicable to such a virtual device, and implemented
only partially now. But may be it could be fixed later at least for
completeness.
MFC after: 2 weeks
if a demotion succeeds, then all of the 4KB page mappings within the
superpage-sized region must be valid, so there is no point in testing the
validity of the 4KB page mapping that is going to be write protected.
Deindent the nearby code.
Reviewed by: kib, markj
Tested by: pho (amd64, i386)
X-MFC after: r350004 (this change depends on arm64 dirty bit emulation)
Differential Revision: https://reviews.freebsd.org/D21027
The timeout field in the CAPS register is defined to be 8 bits, so its type was
uint8_t. We recently started adding 1 to it to cope with rogue devices that
listed 0 timeout time (which is impossible). However, in so doing, other devices
that list 0xff (for a 2 minute timeout) were broken when adding 1
overflowed. Widen the type to be uint32_t like its source register to avoid the
issue.
Reported by: bapt@
ATA sanitize is functionally identical to SCSI, just uses different
initiation commands and status reporting mechanism.
While there, make kernel better handle sanitize commands and statuses.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
Added allocation retry loop in alloc_pvo_entry(), to wait for
memory to become available if the caller specifies the M_WAITOK flag.
Also, the loop in moa64_enter() was removed, as moea64_pvo_enter()
never returns ENOMEM. It is alloc_pvo_entry() memory allocation that
can fail and must be retried.
Reviewed by: jhibbits
Differential Revision: https://reviews.freebsd.org/D21035
This commit is for the correct version. (The incorrect one had the order
of the last two entries reversed, due to my testing with copy_file_range
at 568 instead of 569.) This misordering should not have been a problem,
but is now fixed.
This patch adds support to the kernel for a Linux compatible
copy_file_range(2) syscall and the related VOP_COPY_FILE_RANGE(9).
This syscall/VOP can be used by the NFSv4.2 client to implement the
Copy operation against an NFSv4.2 server to do file copies locally on
the server.
The vn_generic_copy_file_range() function in this patch can be used
by the NFSv4.2 server to implement the Copy operation.
Fuse may also me able to use the VOP_COPY_FILE_RANGE() method.
vn_generic_copy_file_range() attempts to maintain holes in the output
file in the range to be copied, but may fail to do so if the input and
output files are on different file systems with different _PC_MIN_HOLE_SIZE
values.
Separate commits will be done for the generated syscall files and userland
changes. A commit for a compat32 syscall will be done later.
Reviewed by: kib, asomers (plus comments by brooks, jilles)
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D20584
Summary:
It turns out statistics accounting is very expensive in the pmap driver,
and doesn't seem necessary in the common case. Make this optional
behind a MOEA64_STATS #define, which one can set if they really need
statistics.
This saves ~7-8% on buildworld time on a POWER9.
Found by bdragon.
Reviewed by: luporl
Differential Revision: https://reviews.freebsd.org/D20903
turnstile_{lock,unlock}() were added for use in epoch. turnstile_lock()
returned NULL to indicate that the calling thread had lost a race and
the turnstile was no longer associated with the given lock, or the lock
owner. However, reader-writer locks may not have a designated owner,
in which case turnstile_lock() would return NULL and
epoch_block_handler_preempt() would leak spinlocks as a result.
Apply a minimal fix: return the lock owner as a separate return value.
Reviewed by: kib
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21048
Now that we have a way to obtain entropy in capability mode
(getrandom(2)), libcap_random is obsolete. Remove it.
Bump __FreeBSD_version in case anything happens to use it, though I've
found no consumers.
Reviewed by: delphij, emaste, oshogbo
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21033
Commit text by Jake:
If a driver's IFDI_ATTACH_PRE function fails, the iflib_device_register
function will free the ctx pointer. However, it does not reset the
device softc pointer to NULL.
This will result in memory corruption as a future access to the now
invalid pointer will corrupt memory that is later allocated on top of
the same memory location.
The iflib_device_deregister function correctly resets the softc pointer
by using device_set_softc().
This clears up the invalid dangling pointer and prevents memory
corruption that could lead to a panic or undefined behavior if the
device's driver failed to attach.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Submitted by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed by: erj@, gallatin@
MFC after: 1 week
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D21003
The already-listed APMC0D0F ID belongs to the Ampere eMAG aarch64
platform, but ACPI support was not even built on aarch64.
Submitted by: Greg V <greg_unrelenting.technology>
Differential Revision: https://reviews.freebsd.org/D21059
of the TCP TS offset from taking the IP addresses and the TCP port
numbers into account to a version just taking only the IP addresses
into account. This works around broken middleboxes or endpoints.
The default is to keep the behaviour, which is also the behaviour
recommended in RFC 7323.
Reported by: devgs@ukr.net
Reviewed by: rrs@
MFC after: 2 weeks
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D20980
- Wrong order of casting and bit shift caused that enabling and disabling
queues didn't work properly for queues number larger than 32. Use literals
with right suffix instead.
- TX ring tail address was not updated during reinitiailzation of TX
structures. It could block sending traffic.
- Also remove unused variables 'eims' and 'active_queues'.
Submitted by: Krzysztof Galazka <krzysztof.galazka@intel.com>
Reviewed by: erj@
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D20826
Previously only some of the ID register fields were 64 bit. To allow
for a script to generate these mark them all 64 bit. To allow for their
use in assembly we need to use the UINT64_C macro via a new UL macro
to stop the lines from being too long.
MFC after: 1 week
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D20977
After r343631 pfil hooks are invoked in net_epoch_preempt section,
this allows to avoid extra locking. Add NET_EPOCH_ASSER() assertion
to each ipfw_bpf_*tap*() call to require to be called from inside
epoch section.
Use NET_EPOCH_WAIT() in ipfw_clone_destroy() to wait until it becomes
safe to free() ifnet. And use on-stack ifnet pointer in each
ipfw_bpf_*tap*() call to avoid NULL pointer dereference in case when
V_*log_if global variable will become NULL during ipfw_bpf_*tap*() call.
Sponsored by: Yandex LLC
While for ATA disks resize is even more rare situation than for SCSI, it
may happen in case of HPA or AMA being used. Make ATA XPT report minor
IDENTIFY DATA change to upper layers with AC_GETDEV_CHANGED, and ada(4)
periph driver handle that event, recalculating all the disk properties and
signalling resize to GEOM. Since ATA has no mechanism of UNIT ATTENTIONs,
like SCSI, it has no way to detect that something has changed. That is why
this functionality depends on explicit reprobe via XPT_REPROBE_LUN call.
MFC after: 2 weeks
Relnotes: yes
Sponsored by: iXsystems, Inc.
oldpvo is never explicitly NULL'd by moea64_pvo_enter(), so don't check for
NULL to do anything, only check error.
PR: 239372
Reported by: Francis Little
In principle this should not matter as it's a union and they point to
the same memory location but based on the code above we should be
accessing .sata and not .ata.
Submitted by: arichardson
Reviewed by: scottl, imp
Obtained from: CheriBSD
MFC after: 1 week
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D21002
o Add an experimental IOMMU support to xDMA framework
The BERI IOMMU device is the part of CHERI device-model project [1]. It
translates memory addresses for various BERI peripherals modelled in
software. It accepts FreeBSD/mips64 page directories format and manages
BERI TLB.
1. https://github.com/CTSRD-CHERI/device-model
Sponsored by: DARPA, AFRL
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
There are some explicit comparisions of refcount_release(9) result
with 0/1, which are fine.
Reviewed by: markj, mjg
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D21014
we should test ATTR_SW_DBM, not ATTR_AP_RW, to determine whether to set
PGA_WRITEABLE. In effect, we are currently setting PGA_WRITEABLE based on
whether the dirty bit is preset, not whether the mapping is writeable.
Correct this mistake.
Reviewed by: markj
X-MFC with: r350004
Differential Revision: https://reviews.freebsd.org/D21013
fget_unlocked() and fhold().
On sufficiently large machine, f_count can be legitimately very large,
e.g. malicious code can dup same fd up to the per-process
filedescriptors limit, and then fork as much as it can.
On some smaller machine, I see
kern.maxfilesperproc: 939132
kern.maxprocperuid: 34203
which already overflows u_int. More, the malicious code can create
transient references by sending fds over unix sockets.
I realized that this check is missed after reading
https://secfault-security.com/blog/FreeBSD-SA-1902.fd.html
Reviewed by: markj (previous version), mjg
Tested by: pho (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D20947
where the page table entry was previously invalid. (Note that I did not
replace pmap_load_store() when it was followed by a TLB invalidation, even
if we are not using the return value from pmap_load_store().)
Correct an error in pmap_enter(). A test for determining when to set
PGA_WRITEABLE was always true, even if the mapping was read only.
In pmap_enter_l2(), when replacing an empty kernel page table page by a
superpage mapping, clear the old l2 entry and issue a TLB invalidation. My
reading of the ARM architecture manual leads me to believe that the TLB
could hold an intermediate entry referencing the empty kernel page table
page even though it contains no valid mappings.
Replace a couple direct uses of atomic_clear_64() by the new
pmap_clear_bits().
In a couple comments, replace the term "paging-structure caches", which is
an Intel-specific term for the caches that hold intermediate entries in the
page table, with wording that is more consistent with the ARM architecture
manual.
Reviewed by: markj
X-MFC after: r350004
Differential Revision: https://reviews.freebsd.org/D20998
features offered by the chips.
For 2127 and 2129 chips, fix the detection of when chip-init is needed. The
chip config needs to be reset whenever power was lost, but the logic was
wrong for 212x chips (it only worked for 8523). Now the "oscillator
stopped" bit rather than the power manager mode is used to detect startup
after powerfail.
For all chips, disable the clock output pin.
For chips that have a timestamp/tamper-monitor feature, turn off monitoring
of the timestamp trigger pin.
The 8523, 2127, and 2129 chips have a "power manager" feature that offers
several options. We've been using the default mode which enables
everything. Now the code sets the power manager options to
- direct-switch (when Vdd < Vbat, without extra threshold check)
- no battery monitor
- no external powerfail monitor
This reduces the current draw while running on battery from 1930nA to 880nA,
which should roughly double the lifespan of the battery under load.
Because battery checking is a nice thing to have, the code now does a check
at startup, and then once a day after that, instead of checking continuously
(but only actually reporting at startup). The battery check is now done by
setting the power manager back to default mode, sleeping briefly while it
makes a voltage measurement, then switching back to power-saving mode.
I would like to use the name vm_page_release() for a different purpose,
and vm_page_{import,release}() are local to vm_page.c.
Reviewed by: kib
MFC after: 1 week
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
