in_cksum.h required ip.h to be included for struct ip. To be
able to use some general checksum functions like in_addword()
in a non-IPv4 context, limit the (also exported to user space)
IPv4 specific functions to the times, when the ip.h header is
present and IPVERSION is defined (to 4).
We should consider more general checksum (updating) functions
to also allow easier incremental checksum updates in the L3/4
stack and firewalls, as well as ponder further requirements by
certain NIC drivers needing slightly different pseudo values
in offloading cases. Thinking in terms of a better "library".
Sponsored by: The FreeBSD Foundation
Sponsored by: iXsystems
Reviewed by: gnn (as part of the whole)
MFC After: 3 days
to this pmap.c. This new r/w lock is used primarily to synchronize access
to the PV lists. However, it will be used in a somewhat unconventional
way. As finer-grained PV list locking is added to each of the pmap
functions that acquire this r/w lock, its acquisition will be changed from
write to read, enabling concurrent execution of the pmap functions with
finer-grained locking.
Reviewed by: kib
X-MFC after: r235598
longer uses the active and inactive paging queues. Instead, the pmap now
maintains an LRU-ordered list of pv entry pages, and pmap_pv_reclaim() uses
this list to select pv entries for reclamation.
Note: The old pmap_collect() tried to avoid reclaiming mappings for pages
that have either a hold_count or a busy field that is non-zero. However,
this isn't necessary for correctness, and the locking in pmap_collect() was
insufficient to guarantee that such mappings weren't reclaimed. The new
pmap_pv_reclaim() doesn't even try.
Reviewed by: kib
MFC after: 6 weeks
ataraid(4) previously was present there and having GEOM RAID is convinient.
Unlike other classes GEOM RAID can be set up from BIOS before install and
users are expecting it to be detected automatically.
- DTrace scripts to check for errors, performance, ...
they serve mostly as examples of what you can do with the static probe;s
with moderate load the scripts may be overwhelmed, excessive lock-tracing
may influence program behavior (see the last design decission)
Design decissions:
- use "linuxulator" as the provider for the native bitsize; add the
bitsize for the non-native emulation (e.g. "linuxuator32" on amd64)
- Add probes only for locks which are acquired in one function and released
in another function. Locks which are aquired and released in the same
function should be easy to pair in the code, inter-function
locking is more easy to verify in DTrace.
- Probes for locks should be fired after locking and before releasing to
prevent races (to provide data/function stability in DTrace, see the
man-page of "dtrace -v ..." and the corresponding DTrace docs).
intr_bind() on x86.
This has been requested by jhb and I strongly disagree with this,
but as long as he is the x86 and interrupt subsystem maintainer I will
follow his directives.
The disagreement cames from what we should really consider as a
public KPI. IMHO, if we really need a selection between the kernel
functions, we may need an explicit protection like _KERNEL_KPI, which
defines which subset of the kernel function might really be considered
as part of the KPI (for thirdy part modules) and which not.
As long as we don't have this mechanism I just consider any possible
function as usable by thirdy part code, thus intr_bind() included.
MFC after: 1 week
Includes instruction emulation for memory r/w access. This
opens the door for io-apic, local apic, hpet timer, and
legacy device emulation.
Submitted by: ryan dot berryhill at sandvine dot com
Reviewed by: grehan
Obtained from: Sandvine
discrepancy between modules and kernel, but deal with SMP differences
within the functions themselves.
As an added bonus this also helps in terms of code readability.
Requested by: gibbs
Reviewed by: jhb, marius
MFC after: 1 week
but GNU libc used it without checking its kernel version, e. g., Fedora 10.
- Move pipe(2) implementation for Linuxulator from MD files to MI file,
sys/compat/linux/linux_file.c. There is no MD code for this syscall at all.
- Correct an argument type for pipe() from l_ulong * to l_int *. Probably
this was the source of MI/MD confusion.
Reviewed by: emulation
- Mark 'sdp' as requiring 'inet'.
- Always include "opt_inet.h" and "opt_inet6.h" and modify the IB
driver Makefiles to honor WITH/WITHOUT_INET/INET6/_SUPPORT options
to determine what should be enabled during a module build.
- Fix the mlxen(4) driver and the core IB code to compile without
if INET is disabled (including when both INET and INET6 are disabled).
Reviewed by: bz
MFC after: 2 weeks
in set_apic_interrupt_ids(). Besides, set_apic_interrupts_ids() is not
called in the !SMP case too.
Fix this by:
- Adding the BSP as an interrupt target directly in cpu_startup().
- Remove an obsolete optimization where the BSP are skipped in
set_apic_interrupt_ids().
Reported by: jh
Reviewed by: jhb
MFC after: 3 days
X-MFC: r233961
Pointy hat to: me
an uncorrected ECC error tends to fire on all CPUs in a package
simultaneously and the current printf hacks are not sufficient to make
the messages legible. Instead, use the existing mca_lock spinlock to
serialize calls to mca_log() and change the machine check code to panic
directly when an unrecoverable error is encoutered rather than falling
back to a trap_fatal() call in trap() (which adds nearly a screen-full of
logging messages that aren't useful for machine checks).
MFC after: 2 weeks
"Under a highly specific and detailed set of internal timing conditions,
the processor may incorrectly update the stack pointer after a long series
of push and/or near-call instructions, or a long series of pop and/or
near-return instructions. The processor must be in 64-bit mode for this
erratum to occur."
MFC after: 3 days
bridges. Rather than blindly enabling the windows on all of them, only
enable the window when an MSI interrupt is enabled for a device behind
the bridge, similar to what already happens for HT PCI-PCI bridges.
To implement this, each x86 Host-PCI bridge driver has to be able to
locate it's actual backing device on bus 0. For ACPI, use the _ADR
method to find the slot and function of the device. For the non-ACPI
case, the legacy(4) driver already scans bus 0 looking for Host-PCI
bridge devices. Now it saves the slot and function of each bridge that
it finds as ivars that the Host-PCI bridge driver can then use in its
pcib_map_msi() method.
This fixes machines where non-MSI interrupts were broken by the previous
round of HT MSI changes.
Tested by: bapt
MFC after: 1 week
be less ambiguous and more clearly identify what it means. This
attribute is what Intel refers to as UC-, and it's only difference
relative to normal UC memory is that a WC MTRR will override a UC-
PAT entry causing the memory to be treated as WC, whereas a UC PAT
entry will always override the MTRR.
- Remove the VM_MEMATTR_UNCACHED alias from powerpc.
New kernel events can be added at various location for sampling or counting.
This will for example allow easy system profiling whatever the processor is
with known tools like pmcstat(8).
Simultaneous usage of software PMC and hardware PMC is possible, for example
looking at the lock acquire failure, page fault while sampling on
instructions.
Sponsored by: NETASQ
MFC after: 1 month
<20120222095239.Horde.0hpYHJjmRSRPRKzXsoFRbYk@webmail.leidinger.net>.
According to some private emails received, it apparently is not unpopular
to use at least Quad GigaSwift cards driven by cas(4) in x86 machines.
MFC after: 1 week
The GPL infected parts which were blocking the inclusion of snd_csa
and snd_emu10kx in GENERIC have recently been removed from the tree.
I'm also adding snd_cmi to GENERIC, which I originally intended to
add when we enabled sound support by default.
Discussed with: jhb, pfg, Yuriy Tsibizov <yuriy.tsibizov@gfk.ru>
Approved by: jhb
kernel.
When access restrictions are added to a page table entry, we flush the
corresponding virtual address mapping from the TLB. In contrast, when
access restrictions are removed from a page table entry, we do not
flush the virtual address mapping from the TLB. This is exactly as
recommended in AMD's documentation. In effect, when access
restrictions are removed from a page table entry, AMD's MMUs will
transparently refresh a stale TLB entry. In short, this saves us from
having to perform potentially costly TLB flushes. In contrast,
Intel's MMUs are allowed to generate a spurious page fault based upon
the stale TLB entry. Usually, such spurious page faults are handled
by vm_fault() without incident. However, when we are executing
no-fault sections of the kernel, we are not allowed to execute
vm_fault(). This change introduces special-case handling for spurious
page faults that occur in no-fault sections of the kernel.
In collaboration with: kib
Tested by: gibbs (an earlier version)
I would also like to acknowledge Hiroki Sato's assistance in
diagnosing this problem.
MFC after: 1 week
As of FreeBSD 8, this driver should not be used. Applications that use
posix_openpt(2) and openpty(3) use the pts(4) that is built into the
kernel unconditionally. If it turns out high profile depend on the
pty(4) module anyway, I'd rather get those fixed. So please report any
issues to me.
The pty(4) module is still available as a kernel module of course, so a
simple `kldload pty' can be used to run old-style pseudo-terminals.
longer serve any purpose. Prior to r157446, they served a purpose
because there was a fixed amount of kernel virtual address space
reserved for pv entries at boot time. However, since that change pv
entries are accessed through the direct map, and so there is no limit
imposed by a fixed amount of kernel virtual address space.
Fix a couple of nearby style issues.
Reviewed by: jhb, kib
MFC after: 1 week
AcpiEnterSleepState() executes (optional) _GTS method since ACPICA 20120215
(r231844). To evaluate the method, we need malloc(9), which may sleep.
Reported by: bschmidt
MFC after: 3 days
segments.h to a new x86 segments.h.
Add __packed attribute to some structs (just to be sure).
Also make it clear that i386 GDT and LDT entries are used in ia64 code.
excluded from superpage promotions. At least one of the reason is
that pv_table is sized for non-fictitious pages only.
Consistently check for the page to be non-fictitious before accesing
superpage pv list.
Sponsored by: The FreeBSD Foundation
Reviewed by: alc
MFC after: 2 weeks
reg.h with stubs.
The tREGISTER macros are only made visible on i386. These macros are
deprecated and should not be available on amd64.
The i386 and amd64 versions of struct reg have been renamed to struct
__reg32 and struct __reg64. During compilation either __reg32 or __reg64
is defined as reg depending on the machine architecture. On amd64 the i386
struct is also available as struct reg32 which is used in COMPAT_FREEBSD32
code.
Most of compat/ia32/ia32_reg.h is now IA64 only.
Reviewed by: kib (previous version)
field are synchronized, there is no need for pmap_protect() to acquire
the page queues lock unless it is going to access the pv lists.
Reviewed by: kib
Remove FPU types from compat/ia32/ia32_reg.h that are no longer needed.
Create machine/npx.h on amd64 to allow compiling i386 code that uses
this header.
The original npx.h and fpu.h define struct envxmm differently. Both
definitions have been included in the new x86 header as struct __envxmm32
and struct __envxmm64. During compilation either __envxmm32 or __envxmm64
is defined as envxmm depending on machine architecture. On amd64 the i386
struct is also available as struct envxmm32.
Reviewed by: kib
kernel version introduced the sysctl (based upon a linux man-page)
- add comments to sscalls.master regarding some names of sysctls which are
different than the linux-names (based upon the linux unistd.h)
- add some dummy sysctls
- name an unimplemented sysctl
MFC after: 1 month
platforms.
This will make every attempt to mount a non-mpsafe filesystem to the
kernel forbidden, unless it is expressely compiled with
VFS_ALLOW_NONMPSAFE option.
This patch is part of the effort of killing non-MPSAFE filesystems
from the tree.
No MFC is expected for this patch.
Winbond Super I/O chips.
With minor efforts it should be possible the extend the driver to support
further chips/revisions available from Winbond. In the simplest case
only new IDs need to be added, while different chipsets might require
their own function to enter extended function mode, etc.
Sponsored by: Sandvine Incorporated ULC (in 2011)
Reviewed by: emaste, brueffer
MFC after: 2 weeks
amd64/i386/pc98 ptrace.h with stubs.
For amd64 PT_GETXSTATE and PT_SETXSTATE have been redefined to match the
i386 values. The old values are still supported but should no longer be
used.
Reviewed by: kib
amd64/i386/pc98 endian.h with stubs.
In __bswap64_const(x) the conflict between 0xffUL and 0xffULL has been
resolved by reimplementing the macro in terms of __bswap32(x). As a side
effect __bswap64_var(x) is now implemented using two bswap instructions on
i386 and should be much faster. __bswap32_const(x) has been reimplemented
in terms of __bswap16(x) for consistency.
spinlock_enter()/spinlock_exit() to save/restore RFLAGS. We know interrupt
is disabled when returning from S3. For AP, we do not have to save/restore
it because IRET will do it for us any way. Do not save CR3 locally because
savectx() does it and BSP does not have to switch to kernel map for amd64.
Change contigmalloc(9) flag while I am in the neighborhood.
Mask off the first 16 pages unless we appear to be running in a VM. This
address may be overridden by 'hw.physmem.start' tunable from loader.
Note Linux used to have a BIOS quirk table for this issue but it seems they
made it default recently.
both 64bit and 32bit binaries, not for 64bit only.
The set of the flag is not neccessary there, because the only current
user of the cpu_set_user_tls() is create_thread(), which calls
cpu_set_upcall() before and cpu_set_upcall() itself sets PCB_FULL_IRET.
Change the function for consistency and preserve existing KPI for now.
MFC after: 1 week
kernel modules that include binary-only code.
More fine-grained control is provided via MK_SOURCELESS_HOST (for native code
that runs on host CPU) and MK_SOURCELESS_UCODE (for microcode).
Reviewed by: julian, delphij, freebsd-arch
Approved by: kib (mentor)
MFC after: 2 weeks
The isci driver is for the integrated SAS controller in the Intel C600
(Patsburg) chipset. Source files in sys/dev/isci directory are
FreeBSD-specific, and sys/dev/isci/scil subdirectory contains
an OS-agnostic library (SCIL) published by Intel to control the SAS
controller. This library is used primarily as-is in this driver, with
some post-processing to better integrate into the kernel build
environment.
isci.4 and a README in the sys/dev/isci directory contain a few
additional details.
This driver is only built for amd64 and i386 targets.
Sponsored by: Intel
Reviewed by: scottl
Approved by: scottl
excluding other allocations including UMA now entails the addition of
a single flag to kmem_alloc or uma zone create
Reviewed by: alc, avg
MFC after: 2 weeks
64bit and 32bit ABIs. As a side-effect, it enables AVX on capable
CPUs.
In particular:
- Query the CPU support for XSAVE, list of the supported extensions
and the required size of FPU save area. The hw.use_xsave tunable is
provided for disabling XSAVE, and hw.xsave_mask may be used to
select the enabled extensions.
- Remove the FPU save area from PCB and dynamically allocate the
(run-time sized) user save area on the top of the kernel stack,
right above the PCB. Reorganize the thread0 PCB initialization to
postpone it after BSP is queried for save area size.
- The dumppcb, stoppcbs and susppcbs now do not carry the FPU state as
well. FPU state is only useful for suspend, where it is saved in
dynamically allocated suspfpusave area.
- Use XSAVE and XRSTOR to save/restore FPU state, if supported and
enabled.
- Define new mcontext_t flag _MC_HASFPXSTATE, indicating that
mcontext_t has a valid pointer to out-of-struct extended FPU
state. Signal handlers are supplied with stack-allocated fpu
state. The sigreturn(2) and setcontext(2) syscall honour the flag,
allowing the signal handlers to inspect and manipilate extended
state in the interrupted context.
- The getcontext(2) never returns extended state, since there is no
place in the fixed-sized mcontext_t to place variable-sized save
area. And, since mcontext_t is embedded into ucontext_t, makes it
impossible to fix in a reasonable way. Instead of extending
getcontext(2) syscall, provide a sysarch(2) facility to query
extended FPU state.
- Add ptrace(2) support for getting and setting extended state; while
there, implement missed PT_I386_{GET,SET}XMMREGS for 32bit binaries.
- Change fpu_kern KPI to not expose struct fpu_kern_ctx layout to
consumers, making it opaque. Internally, struct fpu_kern_ctx now
contains a space for the extended state. Convert in-kernel consumers
of fpu_kern KPI both on i386 and amd64.
First version of the support for AVX was submitted by Tim Bird
<tim.bird am sony com> on behalf of Sony. This version was written
from scratch.
Tested by: pho (previous version), Yamagi Burmeister <lists yamagi org>
MFC after: 1 month
similarly named CPU instructions.
Since our in-tree binutils gas is not aware of the instructions, and
I have to use the byte-sequence to encode them, hardcode the r/m operand
as (%rdi). This way, first argument of the pseudo-function is already
placed into proper register.
MFC after: 1 week
CTL is a disk and processor device emulation subsystem originally written
for Copan Systems under Linux starting in 2003. It has been shipping in
Copan (now SGI) products since 2005.
It was ported to FreeBSD in 2008, and thanks to an agreement between SGI
(who acquired Copan's assets in 2010) and Spectra Logic in 2010, CTL is
available under a BSD-style license. The intent behind the agreement was
that Spectra would work to get CTL into the FreeBSD tree.
Some CTL features:
- Disk and processor device emulation.
- Tagged queueing
- SCSI task attribute support (ordered, head of queue, simple tags)
- SCSI implicit command ordering support. (e.g. if a read follows a mode
select, the read will be blocked until the mode select completes.)
- Full task management support (abort, LUN reset, target reset, etc.)
- Support for multiple ports
- Support for multiple simultaneous initiators
- Support for multiple simultaneous backing stores
- Persistent reservation support
- Mode sense/select support
- Error injection support
- High Availability support (1)
- All I/O handled in-kernel, no userland context switch overhead.
(1) HA Support is just an API stub, and needs much more to be fully
functional.
ctl.c: The core of CTL. Command handlers and processing,
character driver, and HA support are here.
ctl.h: Basic function declarations and data structures.
ctl_backend.c,
ctl_backend.h: The basic CTL backend API.
ctl_backend_block.c,
ctl_backend_block.h: The block and file backend. This allows for using
a disk or a file as the backing store for a LUN.
Multiple threads are started to do I/O to the
backing device, primarily because the VFS API
requires that to get any concurrency.
ctl_backend_ramdisk.c: A "fake" ramdisk backend. It only allocates a
small amount of memory to act as a source and sink
for reads and writes from an initiator. Therefore
it cannot be used for any real data, but it can be
used to test for throughput. It can also be used
to test initiators' support for extremely large LUNs.
ctl_cmd_table.c: This is a table with all 256 possible SCSI opcodes,
and command handler functions defined for supported
opcodes.
ctl_debug.h: Debugging support.
ctl_error.c,
ctl_error.h: CTL-specific wrappers around the CAM sense building
functions.
ctl_frontend.c,
ctl_frontend.h: These files define the basic CTL frontend port API.
ctl_frontend_cam_sim.c: This is a CTL frontend port that is also a CAM SIM.
This frontend allows for using CTL without any
target-capable hardware. So any LUNs you create in
CTL are visible in CAM via this port.
ctl_frontend_internal.c,
ctl_frontend_internal.h:
This is a frontend port written for Copan to do
some system-specific tasks that required sending
commands into CTL from inside the kernel. This
isn't entirely relevant to FreeBSD in general,
but can perhaps be repurposed.
ctl_ha.h: This is a stubbed-out High Availability API. Much
more is needed for full HA support. See the
comments in the header and the description of what
is needed in the README.ctl.txt file for more
details.
ctl_io.h: This defines most of the core CTL I/O structures.
union ctl_io is conceptually very similar to CAM's
union ccb.
ctl_ioctl.h: This defines all ioctls available through the CTL
character device, and the data structures needed
for those ioctls.
ctl_mem_pool.c,
ctl_mem_pool.h: Generic memory pool implementation used by the
internal frontend.
ctl_private.h: Private data structres (e.g. CTL softc) and
function prototypes. This also includes the SCSI
vendor and product names used by CTL.
ctl_scsi_all.c,
ctl_scsi_all.h: CTL wrappers around CAM sense printing functions.
ctl_ser_table.c: Command serialization table. This defines what
happens when one type of command is followed by
another type of command.
ctl_util.c,
ctl_util.h: CTL utility functions, primarily designed to be
used from userland. See ctladm for the primary
consumer of these functions. These include CDB
building functions.
scsi_ctl.c: CAM target peripheral driver and CTL frontend port.
This is the path into CTL for commands from
target-capable hardware/SIMs.
README.ctl.txt: CTL code features, roadmap, to-do list.
usr.sbin/Makefile: Add ctladm.
ctladm/Makefile,
ctladm/ctladm.8,
ctladm/ctladm.c,
ctladm/ctladm.h,
ctladm/util.c: ctladm(8) is the CTL management utility.
It fills a role similar to camcontrol(8).
It allow configuring LUNs, issuing commands,
injecting errors and various other control
functions.
usr.bin/Makefile: Add ctlstat.
ctlstat/Makefile
ctlstat/ctlstat.8,
ctlstat/ctlstat.c: ctlstat(8) fills a role similar to iostat(8).
It reports I/O statistics for CTL.
sys/conf/files: Add CTL files.
sys/conf/NOTES: Add device ctl.
sys/cam/scsi_all.h: To conform to more recent specs, the inquiry CDB
length field is now 2 bytes long.
Add several mode page definitions for CTL.
sys/cam/scsi_all.c: Handle the new 2 byte inquiry length.
sys/dev/ciss/ciss.c,
sys/dev/ata/atapi-cam.c,
sys/cam/scsi/scsi_targ_bh.c,
scsi_target/scsi_cmds.c,
mlxcontrol/interface.c: Update for 2 byte inquiry length field.
scsi_da.h: Add versions of the format and rigid disk pages
that are in a more reasonable format for CTL.
amd64/conf/GENERIC,
i386/conf/GENERIC,
ia64/conf/GENERIC,
sparc64/conf/GENERIC: Add device ctl.
i386/conf/PAE: The CTL frontend SIM at least does not compile
cleanly on PAE.
Sponsored by: Copan Systems, SGI and Spectra Logic
MFC after: 1 month
are booting inside a VM. There are three reasons to disable this:
o It causes the VM host to believe that all the tested pages or RAM are
in use. This in turn may force the host to page out pages of RAM
belonging to other VMs, or otherwise cause problems with fair resource
sharing on the VM cluster.
o It adds significant time to the boot process (around 1 second/Gig in
testing)
o It is unnecessary - the host should have already verified that the
memory is functional etc.
Note that this simply changes the default when in a VM - it can still be
overridden using the hw.memtest.tests tunable.
MFC after: 4 weeks
configurations for various architectures in FreeBSD 10.x. This allows
basic Capsicum functionality to be used in the default FreeBSD
configuration on non-embedded architectures; process descriptors are not
yet enabled by default.
MFC after: 3 months
Sponsored by: Google, Inc
systems with VT-x/EPT (e.g. Sandybridge Macbooks). This will most
likely work on VMWare Workstation8/Player4 as well. See the VMWare app
note at:
http://communities.vmware.com/docs/DOC-8970
Fusion doesn't propagate the PAT MSR auto save-restore entry/exit
control bits. Deal with this by noting that fact and setting up the
PAT MSR to essentially be a no-op - it is init'd to power-on default,
and a software shadow copy maintained.
Since it is treated as a no-op, o/s settings are essentially ignored.
This may not give correct results, but since the hypervisor is running
nested, a number of bets are already off.
On a quad-core/HT-enabled 'MacBook8,2', nested VMs with 1/2/4 vCPUs were
fired up. The more nested vCPUs the worse the performance, unless the VMs
were started up in multiplexed mode where things worked perfectly up to
the limit of 8 vCPUs.
Reviewed by: neel
back after I fix the breakages on some of our more exotic platforms.
While here, add the driver to the amd64 NOTES, so it can be picked up in LINT
builds.
one. Interestingly, these are actually the default for quite some time
(bus_generic_driver_added(9) since r52045 and bus_generic_print_child(9)
since r52045) but even recently added device drivers do this unnecessarily.
Discussed with: jhb, marcel
- While at it, use DEVMETHOD_END.
Discussed with: jhb
- Also while at it, use __FBSDID.
system calls to provide feed-forward clock management capabilities to
userspace processes. ffclock_getcounter() returns the current value of the
kernel's feed-forward clock counter. ffclock_getestimate() returns the current
feed-forward clock parameter estimates and ffclock_setestimate() updates the
feed-forward clock parameter estimates.
- Document the syscalls in the ffclock.2 man page.
- Regenerate the script-derived syscall related files.
Committed on behalf of Julien Ridoux and Darryl Veitch from the University of
Melbourne, Australia, as part of the FreeBSD Foundation funded "Feed-Forward
Clock Synchronization Algorithms" project.
For more information, see http://www.synclab.org/radclock/
Submitted by: Julien Ridoux (jridoux at unimelb edu au)
defined and will allow consumers, willing to provide options, file and
line to locking requests, to not worry about options redefining the
interfaces.
This is typically useful when there is the need to build another
locking interface on top of the mutex one.
The introduced functions that consumers can use are:
- mtx_lock_flags_
- mtx_unlock_flags_
- mtx_lock_spin_flags_
- mtx_unlock_spin_flags_
- mtx_assert_
- thread_lock_flags_
Spare notes:
- Likely we can get rid of all the 'INVARIANTS' specification in the
ppbus code by using the same macro as done in this patch (but this is
left to the ppbus maintainer)
- all the other locking interfaces may require a similar cleanup, where
the most notable case is sx which will allow a further cleanup of
vm_map locking facilities
- The patch should be fully compatible with older branches, thus a MFC
is previewed (infact it uses all the underlying mechanisms already
present).
Comments review by: eadler, Ben Kaduk
Discussed with: kib, jhb
MFC after: 1 month
The current code mixes the use of `flags' and `mode'. This is a bit
confusing, since the faccessat() function as a `flag' parameter to store
the AT_ flag.
Make this less confusing by using the same name as used in the POSIX
specification -- `amode'.
all the architectures.
The option allows to mount non-MPSAFE filesystem. Without it, the
kernel will refuse to mount a non-MPSAFE filesytem.
This patch is part of the effort of killing non-MPSAFE filesystems
from the tree.
No MFC is expected for this patch.
Tested by: gianni
Reviewed by: kib
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
31, but that vector is reserved.
Without this fix, running dtrace -p <pid> would either cause the target
process to crash or the kernel to page fault.
Obtained from: rpaulo
MFC after: 3days
replace amd(4) with the former in the amd64, i386 and pc98 GENERIC kernel
configuration files. Besides duplicating functionality, amd(4), which
previously also supported the AMD Am53C974, unlike esp(4) is no longer
maintained and has accumulated enough bit rot over time to always cause
a panic during boot as long as at least one target is attached to it
(see PR 124667).
PR: 124667
Obtained from: NetBSD (based on)
MFC after: 3 days
thing when changing the debugging options as part of head becoming a new
stable branch. It may also help people who for one reason or another want
to run head but don't want it slowed down by the debugging support.
Reviewed by: kib
implement a deprecated FPU control interface in addition to the
standard one. To make this clearer, further deprecate ieeefp.h
by not declaring the function prototypes except on architectures
that implement them already.
Currently i386 and amd64 implement the ieeefp.h interface for
compatibility, and for fp[gs]etprec(), which doesn't exist on
most other hardware. Powerpc, sparc64, and ia64 partially implement
it and probably shouldn't, and other architectures don't implement it
at all.
As part of the 8.0-RELEASE cycle this was done in stable/8 (r199112)
but was left alone in head so people could work on fixing an issue that
caused boot failure on some motherboards. Apparently nobody has worked
on it and we are getting reports of boot failure with the 9.0 test builds.
So this time I'll comment out the driver in head (still hoping someone
will work on it) and MFC to stable/9.
Submitted by: Alberto Villa <avilla at FreeBSD dot org>
thanks for their contiued support to FreeBSD.
This is version 10.80.00.003 from codeset 10.2.1 [1]
Obtained from: LSI http://kb.lsi.com/Download16574.aspx [1]
- Replace instances of manual assembly instruction "hlt" call
with halt() function calling.
- In cpu_idle_mwait() avoid races in check to sched_runnable() using
the same pattern used in cpu_idle_hlt() with the 'hlt' instruction.
- Add comments explaining the logic behind the pattern used in
cpu_idle_hlt() and other idle callbacks.
In collabouration with: jhb, mav
Reviewed by: adri, kib
MFC after: 3 weeks
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.
Reviewed by: rwatson
Approved by: re (bz)
the code to have the fall-through path to follow the likely target.
Do not use intermediate register to reload user %rsp.
Proposed by: alc
Reviewed by: alc, jhb
Approved by: re (bz)
MFC after: 2 weeks
sequence. The effect is ~1% on the microbenchmark.
In particular, do not restore registers which are preserved by the
C calling sequence. Align the jump target. Avoid unneeded memory
accesses by calculating some data in syscall entry trampoline.
Reviewed by: jhb
Approved by: re (bz)
MFC after: 2 weeks
flags field. Updates to the atomic flags are performed using the atomic
ops on the containing word, do not require any vm lock to be held, and
are non-blocking. The vm_page_aflag_set(9) and vm_page_aflag_clear(9)
functions are provided to modify afalgs.
Document the changes to flags field to only require the page lock.
Introduce vm_page_reference(9) function to provide a stable KPI and
KBI for filesystems like tmpfs and zfs which need to mark a page as
referenced.
Reviewed by: alc, attilio
Tested by: marius, flo (sparc64); andreast (powerpc, powerpc64)
Approved by: re (bz)
devices supported by puc(4) to work "out of the box" since puc.ko does
not work "out of the box".
Reviewed by: marcel
Approved by: re (kib)
MFC after: 1 week
temporary variable and check with if as TUNABLE_*_FETCH do not
alter values unless successfully found the tunable.
Reported by: jhb, bde
MFC after: 3 days
X-MFC with: r224516
Approved by: re (kib)
kernel for FreeBSD 9.0:
Add a new capability mask argument to fget(9) and friends, allowing system
call code to declare what capabilities are required when an integer file
descriptor is converted into an in-kernel struct file *. With options
CAPABILITIES compiled into the kernel, this enforces capability
protection; without, this change is effectively a no-op.
Some cases require special handling, such as mmap(2), which must preserve
information about the maximum rights at the time of mapping in the memory
map so that they can later be enforced in mprotect(2) -- this is done by
narrowing the rights in the existing max_protection field used for similar
purposes with file permissions.
In namei(9), we assert that the code is not reached from within capability
mode, as we're not yet ready to enforce namespace capabilities there.
This will follow in a later commit.
Update two capability names: CAP_EVENT and CAP_KEVENT become
CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they
represent.
Approved by: re (bz)
Submitted by: jonathan
Sponsored by: Google Inc
to VPO_UNMANAGED (and also making the flag protected by the vm object
lock, instead of vm page queue lock).
- Mark the fake pages with both PG_FICTITIOUS (as it is now) and
VPO_UNMANAGED. As a consequence, pmap code now can use use just
VPO_UNMANAGED to decide whether the page is unmanaged.
Reviewed by: alc
Tested by: pho (x86, previous version), marius (sparc64),
marcel (arm, ia64, powerpc), ray (mips)
Sponsored by: The FreeBSD Foundation
Approved by: re (bz)
NFSCL, NFSD instead of NFSCLIENT, NFSSERVER since
NFSCL and NFSD are now the defaults. The client change is
needed for diskless configurations, so that the root
mount works for fstype nfs.
Reported by seanbru at yahoo-inc.com for i386/XEN.
Approved by: re (hrs)
memtesting, which can easily save seconds to minutes of boot time.
The tunable name is kept general to allow reusing the code in
alternate frameworks.
Requested by: many
Discussed on: arch (a while a go)
Obtained from: Sandvine Incorporated
Reviewed by: sbruno
Approved by: re (kib)
MFC after: 2 weeks
From now on, default values for FreeBSD will be 64 maxiumum supported
CPUs on amd64 and ia64 and 128 for XLP. All the other architectures
seem already capped appropriately (with the exception of sparc64 which
needs further support on jalapeno flavour).
Bump __FreeBSD_version in order to reflect KBI/KPI brekage introduced
during the infrastructure cleanup for supporting MAXCPU > 32. This
covers cpumask_t retiral too.
The switch is considered completed at the present time, so for whatever
bug you may experience that is reconducible to that area, please report
immediately.
Requested by: marcel, jchandra
Tested by: pluknet, sbruno
Approved by: re (kib)
This patch is going to help in cases like mips flavours where you
want a more granular support on MAXCPU.
No MFC is previewed for this patch.
Tested by: pluknet
Approved by: re (kib)
sintrcnt/sintrnames which are symbols containing the size of the 2
tables.
- For amd64/i386 remove the storage of intr* stuff from assembly files.
This area can be widely improved by applying the same to other
architectures and likely finding an unified approach among them and
move the whole code to be MI. More work in this area is expected to
happen fairly soon.
No MFC is previewed for this patch.
Tested by: pluknet
Reviewed by: jhb
Approved by: re (kib)
%rcx as "extensions" in long mode. If any unused bit is set in %rcx, these
instructions cause general protection fault. Fix style nits and synchronize
i386 with amd64.
more explicit comments about what's going on and what future maintainers
need to do when e.g. adding a new operation to a sys_machdep.c.
Approved by: mentor(rwatson), re(bz)
option to vm_object_page_remove() asserts that the specified range of pages
is not mapped, or more precisely that none of these pages have any managed
mappings. Thus, vm_object_page_remove() need not call pmap_remove_all() on
the pages.
This change not only saves time by eliminating pointless calls to
pmap_remove_all(), but it also eliminates an inconsistency in the use of
pmap_remove_all() versus related functions, like pmap_remove_write(). It
eliminates harmless but pointless calls to pmap_remove_all() that were being
performed on PG_UNMANAGED pages.
Update all of the existing assertions on pmap_remove_all() to reflect this
change.
Reviewed by: kib
to do with global namespaces) and CAPABILITIES (which has to do with
constraining file descriptors). Just in case, and because it's a better
name anyway, let's move CAPABILITIES out of the way.
Also, change opt_capabilities.h to opt_capsicum.h; for now, this will
only hold CAPABILITY_MODE, but it will probably also hold the new
CAPABILITIES (implying constrained file descriptors) in the future.
Approved by: rwatson
Sponsored by: Google UK Ltd
resource allocation from an x86 Host-PCI bridge driver so that it can be
reused by the ACPI Host-PCI bridge driver (and eventually the MPTable
Host-PCI bridge driver) instead of duplicating the same logic. Note that
this means that hw.acpi.host_mem_start is now replaced with the
hw.pci.host_mem_start tunable that was already used in the non-ACPI case.
This also removes hw.acpi.host_mem_start on ia64 where it was not
applicable (the implementation was very x86-specific).
While here, adjust the logic to apply the new start address on any
"wildcard" allocation even if that allocation comes from a subset of
the allowable address range.
Reviewed by: imp (1)
The generic sound driver has been added, along with enough
device-specific drivers to support the most common audio
chipsets.
We've discussed enabling it from time to time over the years
and we've received numerous requests from users, so we decided
that shipping 9.0 with working audio by default would be the
best thing to do.
Bug reports should be sent to the multimedia@ mailing list, as
usual.
Approved by: mav
No objection: re
The code has definitely been broken for SCHED_ULE, which is a default
scheduler. It may have been broken for SCHED_4BSD in more subtle ways,
e.g. with manually configured CPU affinities and for interrupt devilery
purposes.
We still provide a way to disable individual CPUs or all hyperthreading
"twin" CPUs before SMP startup. See the UPDATING entry for details.
Interaction between building CPU topology and disabling CPUs still
remains fuzzy: topology is first built using all availble CPUs and then
the disabled CPUs should be "subtracted" from it. That doesn't work
well if the resulting topology becomes non-uniform.
This work is done in cooperation with Attilio Rao who in addition to
reviewing also provided parts of code.
PR: kern/145385
Discussed with: gcooper, ambrisko, mdf, sbruno
Reviewed by: attilio
Tested by: pho, pluknet
X-MFC after: never
This regression was introduced in r213323.
There are probably no Intel cpus that support amd64 mode, but do not
support cpuid level 4, but it's better to keep i386 and amd64 versions
of this code in sync.
Discovered by: pho
Tested by: pho
MFC after: 2 weeks
- Don't always pass the cpuid request to the current CPU as some nodes
we will emulate purely in software.
- Pass in the APIC ID of the virtual CPU so we can return the proper APIC
ID.
- Always report a completely flat topology with no SMT or multicore.
- Report the CPUID2_HV feature and implement support for the 0x40000000
CPUID level.
- Use existing constants from <machine/specialreg.h> when possible and
use cpu_feature2 when checking for VMX support.
There was an assumption by the "callers" of this macro that on "return" the
%rsp will be pointing to the 'vmxctx'. The macro was not doing this and thus
when trying to restore host state on an error from "vmlaunch" or "vmresume"
we were treating the memory locations on the host stack as 'struct vmxctx'.
This led to all sorts of weird bugs like double faults or invalid instruction
faults.
This bug is exposed by the -O2 option used to compile the kernel module. With
the -O2 flag the compiler will optimize the following piece of code:
int loopstart = 1;
...
if (loopstart) {
loopstart = 0;
vmx_launch();
} else
vmx_resume();
into this:
vmx_launch();
Since vmx_launch() and vmx_resume() are declared to be __dead2 functions the
compiler is free to do this. The compiler has no way to know that the
functions return indirectly through vmx_setjmp(). This optimization in turn
leads us to trigger the bug in VMXCTX_GUEST_RESTORE().
With this change we can boot a 8.1 guest on a 9.0 host.
Reported by: jhb@
This was benign because the interruption info field is a 32-bit quantity and
the hardware guarantees that the upper 32-bits are all zeros. But it did make
reading the objdump output very confusing.
run as a 1/2 CPU guest on an 8.1 bhyve host.
bhyve/inout.c
inout.h
fbsdrun.c
- Rather than exiting on accesses to unhandled i/o ports, emulate
hardware by returning -1 on reads and ignoring writes to unhandled
ports. Support the previous mode by allowing a 'strict' parameter
to be set from the command line.
The 8.1 guest kernel was vastly cut down from GENERIC and had no
ISA devices. Booting GENERIC exposes a massive amount of random
touching of i/o ports (hello syscons/vga/atkbdc).
bhyve/consport.c
dev/bvm/bvm_console.c
- implement a simplistic signature for the bvm console by returning
'bv' for an inw on the port. Also, set the priority of the console
to CN_REMOTE if the signature was returned. This works better in
an environment where multiple consoles are in the kernel (hello syscons)
bhyve/rtc.c
- return 0 for the access to RTC_EQUIPMENT (yes, you syscons)
amd64/vmm/x86.c
x86.h
- hide a bunch more CPUID leaf 1 bits from the guest to prevent
cpufreq drivers from probing.
The next step will be to move CPUID handling completely into
user-space. This will allow the full spectrum of changes from
presenting a lowest-common-denominator CPU type/feature set, to
exposing (almost) everything that the host can support.
Reviewed by: neel
Obtained from: NetApp
Note AMD dropped SSE5 extensions in order to avoid ISA overlap with Intel
AVX instructions. The SSE5 bit was recycled as XOP extended instruction
bit, CVT16 was deprecated in favor of F16C (half-precision float conversion
instructions for AVX), and the remaining FMA4 (4-operand FMA instructions)
gained a separate CPUID bit. Replace non-existent references with today's
CPUID specifications.
This branch is now considered frozen: future bhyve development will take
place in a branch off -CURRENT.
sys/dev/bvm/bvm_console.c
sys/dev/bvm/bvm_dbg.c
- simple console driver/gdb debug port used for bringup. supported
by user-space bhyve executable
sys/conf/options.amd64
sys/amd64/amd64/minidump_machdep.c
- allow NKPT to be set in the kernel config file
sys/amd64/conf/GENERIC
- mptable config options; bhyve user-space executable creates an mptable
with number of CPUs, and optional vendor extension
- add bvm console/debug
- set NKPT to 512 to allow loading of large RAM disks from the loader
- include kdb/gdb
sys/amd64/amd64/local_apic.c
sys/amd64/amd64/apic_vector.S
sys/amd64/include/specialreg.h
- if x2apic mode available, use MSRs to access the local APIC, otherwise
fall back to 'classic' MMIO mode
sys/amd64/amd64/mp_machdep.c
- support AP spinup on CPU models that don't have real-mode support by
overwriting the real-mode page with a message that supplies the bhyve
user-space executable with enough information to start the AP directly
in 64-bit mode.
sys/amd64/amd64/vm_machdep.c
- insert pause statements into cpu shutdown busy-wait loops
sys/dev/blackhole/blackhole.c
sys/modules/blackhole/Makefile
- boot-time loadable module that claims all PCI bus/slot/funcs specified
in an env var that are to be used for PCI passthrough
sys/amd64/amd64/intr_machdep.c
- allow round-robin assignment of device interrupts to CPUs to be disabled
from the loader
sys/amd64/include/bus.h
- convert string ins/outs instructions to loops of individual in/out since
bhyve doesn't support these yet
sys/kern/subr_bus.c
- if the device was no created with a fixed devclass, then remove it's
association with the devclass it was associated with during probe.
Otherwise, new drivers do not get a chance to probe/attach since the
device will stay married to the first driver that it probed successfully
but failed to attach.
Sponsored by: NetApp, Inc.
architectures (i386, for example) the virtual memory space may be
constrained enough that 2MB is a large chunk. Use 64K for arches
other than amd64 and ia64, with special handling for sparc64 due to
differing hardware.
Also commit the comment changes to kmem_init_zero_region() that I
missed due to not saving the file. (Darn the unfamiliar development
environment).
Arch maintainers, please feel free to adjust ZERO_REGION_SIZE as you
see fit.
Requested by: alc
MFC after: 1 week
MFC with: r221853
vmm.ko - kernel module for VT-x, VT-d and hypervisor control
bhyve - user-space sequencer and i/o emulation
vmmctl - dump of hypervisor register state
libvmm - front-end to vmm.ko chardev interface
bhyve was designed and implemented by Neel Natu.
Thanks to the following folk from NetApp who helped to make this available:
Joe CaraDonna
Peter Snyder
Jeff Heller
Sandeep Mann
Steve Miller
Brian Pawlowski
when the user has indicated that the system has synchronized TSCs or it has
P-state invariant TSCs. For the former case, we may clear the tunable if it
fails the test to prevent accidental foot-shooting. For the latter case, we
may set it if it passes the test to notify the user that it may be usable.
This also introduces a new detection path for family 10h and newer
pre-bulldozer cpus, pre-10h hardware should not be affected.
Tested by: Gary Jennejohn <gljennjohn@googlemail.com>
(with pre-10h hardware)
MFC after: 2 weeks
cpuset_t objects.
That is going to offer the underlying support for a simple bump of
MAXCPU and then support for number of cpus > 32 (as it is today).
Right now, cpumask_t is an int, 32 bits on all our supported architecture.
cpumask_t on the other side is implemented as an array of longs, and
easilly extendible by definition.
The architectures touched by this commit are the following:
- amd64
- i386
- pc98
- arm
- ia64
- XEN
while the others are still missing.
Userland is believed to be fully converted with the changes contained
here.
Some technical notes:
- This commit may be considered an ABI nop for all the architectures
different from amd64 and ia64 (and sparc64 in the future)
- per-cpu members, which are now converted to cpuset_t, needs to be
accessed avoiding migration, because the size of cpuset_t should be
considered unknown
- size of cpuset_t objects is different from kernel and userland (this is
primirally done in order to leave some more space in userland to cope
with KBI extensions). If you need to access kernel cpuset_t from the
userland please refer to example in this patch on how to do that
correctly (kgdb may be a good source, for example).
- Support for other architectures is going to be added soon
- Only MAXCPU for amd64 is bumped now
The patch has been tested by sbruno and Nicholas Esborn on opteron
4 x 12 pack CPUs. More testing on big SMP is expected to came soon.
pluknet tested the patch with his 8-ways on both amd64 and i386.
Tested by: pluknet, sbruno, gianni, Nicholas Esborn
Reviewed by: jeff, jhb, sbruno
driver would verify that requests for child devices were confined to any
existing I/O windows, but the driver relied on the firmware to initialize
the windows and would never grow the windows for new requests. Now the
driver actively manages the I/O windows.
This is implemented by allocating a bus resource for each I/O window from
the parent PCI bus and suballocating that resource to child devices. The
suballocations are managed by creating an rman for each I/O window. The
suballocated resources are mapped by passing the bus_activate_resource()
call up to the parent PCI bus. Windows are grown when needed by using
bus_adjust_resource() to adjust the resource allocated from the parent PCI
bus. If the adjust request succeeds, the window is adjusted and the
suballocation request for the child device is retried.
When growing a window, the rman_first_free_region() and
rman_last_free_region() routines are used to determine if the front or
end of the existing I/O window is free. From using that, the smallest
ranges that need to be added to either the front or back of the window
are computed. The driver will first try to grow the window in whichever
direction requires the smallest growth first followed by the other
direction if that fails.
Subtractive bridges will first attempt to satisfy requests for child
resources from I/O windows (including attempts to grow the windows). If
that fails, the request is passed up to the parent PCI bus directly
however.
The PCI-PCI bridge driver will try to use firmware-assigned ranges for
child BARs first and only allocate a "fresh" range if that specific range
cannot be accommodated in the I/O window. This allows systems where the
firmware assigns resources during boot but later wipes the I/O windows
(some ACPI BIOSen are known to do this) to "rediscover" the original I/O
window ranges.
The ACPI Host-PCI bridge driver has been adjusted to correctly honor
hw.acpi.host_mem_start and the I/O port equivalent when a PCI-PCI bridge
makes a wildcard request for an I/O window range.
The new PCI-PCI bridge driver is only enabled if the NEW_PCIB kernel option
is enabled. This is a transition aide to allow platforms that do not
yet support bus_activate_resource() and bus_adjust_resource() in their
Host-PCI bridge drivers (and possibly other drivers as needed) to use the
old driver for now. Once all platforms support the new driver, the
kernel option and old driver will be removed.
PR: kern/143874 kern/149306
Tested by: mav
function on the possibility of a thread to not preempt.
As this function is very tied to x86 (interrupts disabled checkings)
it is not intended to be used in MI code.
disk dumping.
With the option SW_WATCHDOG on, these operations are doomed to let
watchdog fire, fi they take too long.
I implemented the stubs this way because I really want wdog_kern_*
KPI to not be dependant by SW_WATCHDOG being on (and really, the option
only enables watchdog activation in hardclock) and also avoid to
call them when not necessary (avoiding not-volountary watchdog
activations).
Sponsored by: Sandvine Incorporated
Discussed with: emaste, des
MFC after: 2 weeks
NFS client (which I guess is no longer experimental). The fstype "newnfs"
is now "nfs" and the regular/old NFS client is now fstype "oldnfs".
Although mounts via fstype "nfs" will usually work without userland
changes, an updated mount_nfs(8) binary is needed for kernels built with
"options NFSCL" but not "options NFSCLIENT". Updated mount_nfs(8) and
mount(8) binaries are needed to do mounts for fstype "oldnfs".
The GENERIC kernel configs have been changed to use options
NFSCL and NFSD (the new client and server) instead of NFSCLIENT and NFSSERVER.
For kernels being used on diskless NFS root systems, "options NFSCL"
must be in the kernel config.
Discussed on freebsd-fs@.
device in /dev/ create symbolic link with adY name, trying to mimic old ATA
numbering. Imitation is not complete, but should be enough in most cases to
mount file systems without touching /etc/fstab.
- To know what behavior to mimic, restore ATA_STATIC_ID option in cases
where it was present before.
- Add some more details to UPDATING.
counting memory being dumped in 16MB increments is somewhat silly.
Especially if the dump fails and everything you've got for debugging
is screen filled with numbers in 16 decrements... Replace that with
percentage-based progress with max 10 updates all fitting into one
line.
Collapse other very "useful" piece of crash information (total ram) into
the same line to save some more space.
MFC after: 1 week
set the f_flags field of "struct statfs". This had the interesting
effect of making the NFSv4 mounts "disappear" after r221014,
since NFSMNT_NFSV4 and MNT_IGNORE became the same bit.
Move the files used for a diskless NFS root from sys/nfsclient
to sys/nfs in preparation for them to be used by both NFS
clients. Also, move the declaration of the three global data
structures from sys/nfsclient/nfs_vfsops.c to sys/nfs/nfs_diskless.c
so that they are defined when either client uses them.
Reviewed by: jhb
MFC after: 2 weeks
stack. It means that all legacy ATA drivers are disabled and replaced by
respective CAM drivers. If you are using ATA device names in /etc/fstab or
other places, make sure to update them respectively (adX -> adaY,
acdX -> cdY, afdX -> daY, astX -> saY, where 'Y's are the sequential
numbers for each type in order of detection, unless configured otherwise
with tunables, see cam(4)).
ataraid(4) functionality is now supported by the RAID GEOM class.
To use it you can load geom_raid kernel module and use graid(8) tool
for management. Instead of /dev/arX device names, use /dev/raid/rX.
Add pmap_invalidate_cache_pages() method on x86. It flushes the CPU
cache for the set of pages, which are not neccessary mapped. Since its
supposed use is to prepare the move of the pages ownership to a device
that does not snoop all CPU accesses to the main memory (read GPU in
GMCH), do not rely on CPU self-snoop feature.
amd64 implementation takes advantage of the direct map. On i386,
extract the helper pmap_flush_page() from pmap_page_set_memattr(), and
use it to make a temporary mapping of the flushed page.
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
32 bits. Some times compiler inserts unnecessary instructions to preserve
unused upper 32 bits even when it is casted to a 32-bit value. It reduces
such compiler mistakes where every cycle counts.
