Commit Graph

2117 Commits

Author SHA1 Message Date
Ed Maste
294246bb7d Revert r274772: it is not valid on MIPS
Reported by:	sbruno
2014-11-25 03:50:31 +00:00
Ed Maste
688fd61ae8 Use canonical __PIC__ flag
It is automatically set when -fPIC is passed to the compiler.

Reviewed by:	dim, kib
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D1179
2014-11-21 02:05:48 +00:00
Alexander V. Chernikov
603eaf792b Renove faith(4) and faithd(8) from base. It looks like industry
have chosen different (and more traditional) stateless/statuful
NAT64 as translation mechanism. Last non-trivial commits to both
faith(4) and faithd(8) happened more than 12 years ago, so I assume
it is time to drop RFC3142 in FreeBSD.

No objections from:	net@
2014-11-09 21:33:01 +00:00
Konstantin Belousov
4f3dc90023 Add fueword(9) and casueword(9) functions. They are like fuword(9)
and casuword(9), but do not mix value read and indication of fault.

I know (or remember) enough assembly to handle x86 and powerpc.  For
arm, mips and sparc64, implement fueword() and casueword() as wrappers
around fuword() and casuword(), which means that the functions cannot
distinguish between -1 and fault.

On architectures where fueword() and casueword() are native, implement
fuword() and casuword() using fueword() and casuword(), to reduce
assembly code duplication.

Sponsored by:	The FreeBSD Foundation
Tested by:	pho
MFC after:	2 weeks (ia64 needs treating)
2014-10-28 15:22:13 +00:00
Alan Cox
b17af71943 Simplify memrw().
MFC after:	10 days
2014-10-27 01:10:40 +00:00
John Baldwin
7d313e7bdb Add COMPAT_FREEBSD9 and COMPAT_FREEBSD10 options to wrap code that
provides compatability for FreeBSD 9.x and 10.x binaries.  Enable
these options in kernel configs that enable other COMPAT_FREEBSD<n>
options.
2014-10-24 19:58:24 +00:00
Davide Italiano
2be111bf7d Follow up to r225617. In order to maximize the re-usability of kernel code
in userland rename in-kernel getenv()/setenv() to kern_setenv()/kern_getenv().
This fixes a namespace collision with libc symbols.

Submitted by:   kmacy
Tested by:      make universe
2014-10-16 18:04:43 +00:00
Baptiste Daroussin
dbacd66928 Fix typo revealed by using newer binutils
Differential Revision:	https://reviews.freebsd.org/D933
Reviewed by:	marius
2014-10-10 14:18:33 +00:00
Roger Pau Monné
c98a2727cc ddb: allow specifying the exact address of the symtab and strtab
When the FreeBSD kernel is loaded from Xen the symtab and strtab are
not loaded the same way as the native boot loader. This patch adds
three new global variables to ddb that can be used to specify the
exact position and size of those tables, so they can be directly used
as parameters to db_add_symbol_table. A new helper is introduced, so callers
that used to set ksym_start and ksym_end can use this helper to set the new
variables.

It also adds support for loading them from the Xen PVH port, that was
previously missing those tables.

Sponsored by: Citrix Systems R&D
Reviewed by:	kib

ddb/db_main.c:
 - Add three new global variables: ksymtab, kstrtab, ksymtab_size that
   can be used to specify the position and size of the symtab and
   strtab.
 - Use those new variables in db_init in order to call db_add_symbol_table.
 - Move the logic in db_init to db_fetch_symtab in order to set ksymtab,
   kstrtab, ksymtab_size from ksym_start and ksym_end.

ddb/ddb.h:
 - Add prototype for db_fetch_ksymtab.
 - Declate the extern variables ksymtab, kstrtab and ksymtab_size.

x86/xen/pv.c:
 - Add support for finding the symtab and strtab when booted as a Xen
   PVH guest. Since Xen loads the symtab and strtab as NetBSD expects
   to find them we have to adapt and use the same method.

amd64/amd64/machdep.c:
arm/arm/machdep.c:
i386/i386/machdep.c:
mips/mips/machdep.c:
pc98/pc98/machdep.c:
powerpc/aim/machdep.c:
powerpc/booke/machdep.c:
sparc64/sparc64/machdep.c:
 - Use the newly introduced db_fetch_ksymtab in order to set ksymtab,
   kstrtab and ksymtab_size.
2014-09-25 08:28:10 +00:00
John Baldwin
1f895058e4 Revert unrelated changes accidentally committed in r271192. 2014-09-17 18:55:39 +00:00
Adrian Chadd
066da8050b Migrate ie->ie_assign_cpu and associated code to use an int for CPU rather
than u_char.

Migrate post_filter to use an int for a CPU rather than u_char.

Change intr_event_bind() to use an int for CPU rather than u_char.

It touches the ppc, sparc64, arm and mips machdep code but it should
(hah!) be a no-op.

Tested:

* i386, AMD64 laptops

Reviewed by:	jhb
2014-09-17 17:33:22 +00:00
John Baldwin
b1d735ba4c Create a separate structure for per-CPU state saved across suspend and
resume that is a superset of a pcb.  Move the FPU state out of the pcb and
into this new structure.  As part of this, move the FPU resume code on
amd64 into a C function.  This allows resumectx() to still operate only on
a pcb and more closely mirrors the i386 code.

Reviewed by:	kib (earlier version)
2014-09-06 15:23:28 +00:00
Konstantin Belousov
8158a32900 For CPUs which do hardware cache line unaliasing, use direct map to
access sfbufs.

Suggested and reviewed by:	alc
Tested by:	Michael Moll <kvedulv@kvedulv.de>
Sponsored by:	The FreeBSD Foundation
2014-08-23 18:11:54 +00:00
Konstantin Belousov
5e1d15a879 Complete r254667, do not destroy pmap lock if KVA allocation failed.
Submitted by:	Svatopluk Kraus <onwahe@gmail.com>
MFC after:	1 week
2014-08-16 08:31:25 +00:00
Konstantin Belousov
bb0a8f248d On sparc64, do not keep mappings for the destroyed sf_bufs. Sparc64
pmap, unlike i386, and similar to i386/xen pv, does not tolerate
abandoned mappings for the freed pages.

Reported and tested by:	dumbbell
Diagnosed and reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
2014-08-10 16:59:39 +00:00
Konstantin Belousov
39ffa8c138 Change pmap_enter(9) interface to take flags parameter and superpage
mapping size (currently unused).  The flags includes the fault access
bits, wired flag as PMAP_ENTER_WIRED, and a new flag
PMAP_ENTER_NOSLEEP to indicate that pmap should not sleep.

For powerpc aim both 32 and 64 bit, fix implementation to ensure that
the requested mapping is created when PMAP_ENTER_NOSLEEP is not
specified, in particular, wait for the available memory required to
proceed.

In collaboration with:	alc
Tested by:	nwhitehorn (ppc aim32 and booke)
Sponsored by:	The FreeBSD Foundation and EMC / Isilon Storage Division
MFC after:	2 weeks
2014-08-08 17:12:03 +00:00
Gleb Smirnoff
c8d2ffd6a7 Merge all MD sf_buf allocators into one MI, residing in kern/subr_sfbuf.c
The MD allocators were very common, however there were some minor
differencies. These differencies were all consolidated in the MI allocator,
under ifdefs. The defines from machine/vmparam.h turn on features required
for a particular machine. For details look in the comment in sys/sf_buf.h.

As result no MD code left in sys/*/*/vm_machdep.c. Some arches still have
machine/sf_buf.h, which is usually quite small.

Tested by:	glebius (i386), tuexen (arm32), kevlo (arm32)
Reviewed by:	kib
Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2014-08-05 09:44:10 +00:00
Alan Cox
a695d9b25b Retire pmap_change_wiring(). We have never used it to wire virtual pages.
We continue to use pmap_enter() for that.  For unwiring virtual pages, we
now use pmap_unwire(), which unwires a range of virtual addresses instead
of a single virtual page.

Sponsored by:	EMC / Isilon Storage Division
2014-08-03 20:40:51 +00:00
Nathan Whitehorn
190d685037 Add vt(4) support to sparc64. The only driver currently present (ofwfb)
provides support for a variety of low-end graphics hardware (SBus adapters,
Mach64, QEMU's framebuffer, XVR-100). A driver for at least the Creator3D
cards will have to be present before this can become the default console
driver.

To test vt(4) on sparc64, set kern.vty=vt at the loader prompt.
2014-08-02 03:48:16 +00:00
Gavin Atkinson
f6b4f5ca21 Add error return to dumpsys(), and use it in doadump().
This commit does not add error returns to minidumpsys() or
textdump_dumpsys(); those can also be added later.

Submitted by:	Conrad Meyer (EMC / Isilon storage division)
2014-07-25 23:52:53 +00:00
Alan Cox
09132ba6ac Introduce pmap_unwire(). It will replace pmap_change_wiring(). There are
several reasons for this change:

pmap_change_wiring() has never (in my memory) been used to set the wired
attribute on a virtual page.  We have always used pmap_enter() to do that.
Moreover, it is not really safe to use pmap_change_wiring() to set the wired
attribute on a virtual page.  The description of pmap_change_wiring() says
that it assumes the existence of a mapping in the pmap.  However, non-wired
mappings may be reclaimed by the pmap at any time.  (See pmap_collect().)
Many implementations of pmap_change_wiring() will crash if the mapping does
not exist.

pmap_unwire() accepts a range of virtual addresses, whereas
pmap_change_wiring() acts upon a single virtual page.  Since we are
typically unwiring a range of virtual addresses, pmap_unwire() will be more
efficient.  Moreover, pmap_unwire() allows us to unwire superpage mappings.
Previously, we were forced to demote the superpage mapping, because
pmap_change_wiring() only allowed us to express the unwiring of a single
base page mapping at a time.  This added to the overhead of unwiring for
large ranges of addresses, including the implicit unwiring that occurs at
process termination.

Implementations for arm and powerpc will follow.

Discussed with:	jeff, marcel
Reviewed by:	kib
Sponsored by:	EMC / Isilon Storage Division
2014-07-06 17:42:38 +00:00
Hans Petter Selasky
af3b2549c4 Pull in r267961 and r267973 again. Fix for issues reported will follow. 2014-06-28 03:56:17 +00:00
Glen Barber
37a107a407 Revert r267961, r267973:
These changes prevent sysctl(8) from returning proper output,
such as:

 1) no output from sysctl(8)
 2) erroneously returning ENOMEM with tools like truss(1)
    or uname(1)
 truss: can not get etype: Cannot allocate memory
2014-06-27 22:05:21 +00:00
Hans Petter Selasky
3da1cf1e88 Extend the meaning of the CTLFLAG_TUN flag to automatically check if
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.

Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.

MFC after:	2 weeks
Sponsored by:	Mellanox Technologies
2014-06-27 16:33:43 +00:00
Warner Losh
3f1afabf09 Restore comments accidentally removed.
MFC after: 3 days
2014-06-06 04:08:55 +00:00
Kenneth D. Merry
991554f2c4 Bring in the mpr(4) driver for LSI's MPT3 12Gb SAS controllers.
This is derived from the mps(4) driver, but it supports only the 12Gb
IT and IR hardware including the SAS 3004, SAS 3008 and SAS 3108.

Some notes about this driver:
 o The 12Gb hardware can do "FastPath" I/O, and that capability is included in
   this driver.

 o WarpDrive functionality has been removed, since it isn't supported in
   the 12Gb driver interface.

 o The Scatter/Gather list handling code is significantly different between
   the 6Gb and 12Gb hardware.  The 12Gb boards support IEEE Scatter/Gather
   lists.

Thanks to LSI for developing and testing this driver for FreeBSD.

share/man/man4/mpr.4:
	mpr(4) man page.

sys/dev/mpr/*:
	mpr(4) driver files.

sys/modules/Makefile,
sys/modules/mpr/Makefile:
	Add a module Makefile for the mpr(4) driver.

sys/conf/files:
	Add the mpr(4) driver.

sys/amd64/conf/GENERIC,
sys/i386/conf/GENERIC,
sys/mips/conf/OCTEON1,
sys/sparc64/conf/GENERIC:
	Add the mpr(4) driver to all config files that currently
	have the mps(4) driver.

sys/ia64/conf/GENERIC:
	Add the mps(4) and mpr(4) drivers to the ia64 GENERIC
	config file.

sys/i386/conf/XEN:
	Exclude the mpr module from building here.

Submitted by:	Steve McConnell <Stephen.McConnell@lsi.com>
MFC after:	3 days
Tested by:	Chris Reeves <chrisr@spectralogic.com>
Sponsored by:	LSI, Spectra Logic
Relnotes:	LSI 12Gb SAS driver mpr(4) added
2014-05-02 20:25:09 +00:00
Scott Long
60ad8150c7 Retire smp_active. It was racey and caused demonstrated problems with
the cpufreq code.  Replace its use with smp_started.  There's at least
one userland tool that still looks at the kern.smp.active sysctl, so
preserve it but point it to smp_started as well.

Discussed with: peter, jhb
MFC after: 3 days
Obtained from: Netflix
2014-04-26 20:27:54 +00:00
Tijl Coosemans
0a4c54d606 Rename __wchar_t so it no longer conflicts with __wchar_t from clang 3.4
-fms-extensions.

MFC after:	2 weeks
2014-04-01 14:46:11 +00:00
Warner Losh
3ad1a09169 Rather than require a makeoptions DEBUG to get debug correct,
add it in kern.mk, but only if we're using clang. While this
option is supported by both clang and gcc, in the future there
may be changes to clang which change the defaults that require
a tweak to build our kernel such that other tools in our tree
will work. Set a good example by forcing -gdwarf-2 only for
clang builds, and only if the user hasn't specified another
dwarf level already. Update UPDATING to reflect the changed
state of affairs. This also keeps us from having to update
all the ARM kernels to add this, and also keeps us from
in the future having to update all the MIPS kernels and is
one less place the user will have to know to do something
special for clang and one less thing developers will need
to do when moving an architecture to clang.

Reviewed by:	ian@
MFC after:	1 week
2014-03-25 22:08:31 +00:00
Bryan Drewery
44f1c91610 Rename global cnt to vm_cnt to avoid shadowing.
To reduce the diff struct pcu.cnt field was not renamed, so
PCPU_OP(cnt.field) is still used. pc_cnt and pcpu are also used in
kvm(3) and vmstat(8). The goal was to not affect externally used KPI.

Bump __FreeBSD_version_ in case some out-of-tree module/code relies on the
the global cnt variable.

Exp-run revealed no ports using it directly.

No objection from:	arch@
Sponsored by:	EMC / Isilon Storage Division
2014-03-22 10:26:09 +00:00
Robert Watson
4a14441044 Update kernel inclusions of capability.h to use capsicum.h instead; some
further refinement is required as some device drivers intended to be
portable over FreeBSD versions rely on __FreeBSD_version to decide whether
to include capability.h.

MFC after:	3 weeks
2014-03-16 10:55:57 +00:00
Warner Losh
22b8ff24b5 Delete stray clause 3 (Advertising clause) and renumber while i'm
here.

Approved by: alc@
2014-03-11 23:41:35 +00:00
Dimitry Andric
c3bb517174 Merge from head up to r262472. 2014-02-25 07:40:37 +00:00
Dimitry Andric
362a42b214 Make sure a for loop in fire_alloc_msix() terminates, by making the loop
counter signed.

Reviewed by:	marius
MFC after:	3 days
2014-02-25 07:33:28 +00:00
Dimitry Andric
ad3d02dd2a In sys/sparc64/sparc64/spitfire.c, prevent signed shift overflow by
casting to the appropriate type.  (Note this fix cannot be done in
sys/sparc64/sparc64/spitfire.c, since that file is also included by
assembly source files.)

Reviewed by:	marius
MFC after:	3 days
2014-02-25 07:28:51 +00:00
Dimitry Andric
defb3353ee Similar to r261991, for compiling the GENERIC kernel on sparc64,
explicitly use -gdwarf-2 for the debug symbols.
2014-02-23 19:18:04 +00:00
Dimitry Andric
2994da7d3c Remove more superfluous const specifiers. 2014-02-23 18:36:45 +00:00
John Baldwin
4edef187b8 Add support for managing PCI bus numbers. As with BARs and PCI-PCI bridge
I/O windows, the default is to preserve the firmware-assigned resources.
PCI bus numbers are only managed if NEW_PCIB is enabled and the architecture
defines a PCI_RES_BUS resource type.
- Add a helper API to create top-level PCI bus resource managers for each
  PCI domain/segment.  Host-PCI bridge drivers use this API to allocate
  bus numbers from their associated domain.
- Change the PCI bus and CardBus drivers to allocate a bus resource for
  their bus number from the parent PCI bridge device.
- Change the PCI-PCI and PCI-CardBus bridge drivers to allocate the
  full range of bus numbers from secbus to subbus from their parent bridge.
  The drivers also always program their primary bus register.  The bridge
  drivers also support growing their bus range by extending the bus resource
  and updating subbus to match the larger range.
- Add support for managing PCI bus resources to the Host-PCI bridge drivers
  used for amd64 and i386 (acpi_pcib, mptable_pcib, legacy_pcib, and qpi_pcib).
- Define a PCI_RES_BUS resource type for amd64 and i386.

Reviewed by:	imp
MFC after:	1 month
2014-02-12 04:30:37 +00:00
Nathan Whitehorn
95e3bfe889 Simplify the ofw_bus_lookup_imap() API slightly: make it allocate maskbuf
internally instead of requiring the caller to allocate it.
2013-12-17 15:11:24 +00:00
Marius Strobl
820677f94a Restore a vital comment nuked in r259016. 2013-12-08 15:25:19 +00:00
Aleksandr Rybalko
27cf7d04ef Merge VT(9) project (a.k.a. newcons).
Reviewed by:	nwhitehorn
MFC_to_10_after:	re approval

Sponsored by:	The FreeBSD Foundation
2013-12-05 22:38:53 +00:00
Pawel Jakub Dawidek
f2b525e6b9 Make process descriptors standard part of the kernel. rwhod(8) already
requires process descriptors to work and having PROCDESC in GENERIC
seems not enough, especially that we hope to have more and more consumers
in the base.

MFC after:	3 days
2013-11-30 15:08:35 +00:00
Alan Cox
c70af4875e As of r257209, all architectures have defined VM_KMEM_SIZE_SCALE. In other
words, every architecture is now auto-sizing the kmem arena.  This revision
changes kmeminit() so that the definition of VM_KMEM_SIZE_SCALE becomes
mandatory and the definition of VM_KMEM_SIZE becomes optional.

Replace or eliminate all existing definitions of VM_KMEM_SIZE.  With
auto-sizing enabled, VM_KMEM_SIZE effectively became an alternate spelling
for VM_KMEM_SIZE_MIN on most architectures.  Use VM_KMEM_SIZE_MIN for
clarity.

Change kmeminit() so that the effect of defining VM_KMEM_SIZE is similar to
that of setting the tunable vm.kmem_size.  Whereas the macros
VM_KMEM_SIZE_{MAX,MIN,SCALE} have had the same effect as the tunables
vm.kmem_size_{max,min,scale}, the effects of VM_KMEM_SIZE and vm.kmem_size
have been distinct.  In particular, whereas VM_KMEM_SIZE was overridden by
VM_KMEM_SIZE_{MAX,MIN,SCALE} and vm.kmem_size_{max,min,scale}, vm.kmem_size
was not.  Remedy this inconsistency.  Now, VM_KMEM_SIZE can be used to set
the size of the kmem arena at compile-time without that value being
overridden by auto-sizing.

Update the nearby comments to reflect the kmem submap being replaced by the
kmem arena.  Stop duplicating the auto-sizing formula in every machine-
dependent vmparam.h and place it in kmeminit() where auto-sizing takes
place.

Reviewed by:	kib (an earlier version)
Sponsored by:	EMC / Isilon Storage Division
2013-11-08 16:25:00 +00:00
Konstantin Belousov
80938e75f0 Add bus_dmamap_load_ma() function to load map with the array of
vm_pages.  Provide trivial implementation which forwards the load to
_bus_dmamap_load_phys() page by page.  Right now all architectures use
bus_dmamap_load_ma_triv().

Tested by:	pho (as part of the functional patch)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
2013-10-27 21:39:16 +00:00
Marius Strobl
2ce472e736 Move the implementation of bus_space_barrier(9) to the inline function in
the header. Actually, there's only one version for all types of busses, so
it doesn't make sense to walk up the hierarchy.
2013-10-24 17:06:41 +00:00
Marius Strobl
d1b111bea8 Implement GET_STACK_USAGE.
Discussed with:	mav

Approved by:	re (kib)
MFC after:	1 week
2013-09-29 13:09:25 +00:00
Gleb Smirnoff
255c1caae3 - Create kern.ipc.sendfile namespace, and put the new "readhead" OID
there as "kern.ipc.sendfile.readahead".
- Push all nsfbuf related tunables into MD code. Don't move them
  to new namespace in favor of POLA.

Reviewed by:	scottl
Approved by:	re (gjb)
2013-09-22 13:36:52 +00:00
Alan Cox
deb179bb4c The pmap function pmap_clear_reference() is no longer used. Remove it.
pmap_clear_reference() has had exactly one caller in the kernel for
several years, more precisely, since FreeBSD 8.  Now, that call no
longer exists.

Approved by:	re (kib)
Sponsored by:	EMC / Isilon Storage Division
2013-09-20 04:30:18 +00:00
Pawel Jakub Dawidek
3fded357af Fix panic in ktrcapfail() when no capability rights are passed.
While here, correct all consumers to pass NULL instead of 0 as we pass
capability rights as pointers now, not uint64_t.

Reported by:	Daniel Peyrolon
Tested by:	Daniel Peyrolon
Approved by:	re (marius)
2013-09-18 19:26:08 +00:00
John Baldwin
edb572a38c Add a mmap flag (MAP_32BIT) on 64-bit platforms to request that a mapping use
an address in the first 2GB of the process's address space.  This flag should
have the same semantics as the same flag on Linux.

To facilitate this, add a new parameter to vm_map_find() that specifies an
optional maximum virtual address.  While here, fix several callers of
vm_map_find() to use a VMFS_* constant for the findspace argument instead of
TRUE and FALSE.

Reviewed by:	alc
Approved by:	re (kib)
2013-09-09 18:11:59 +00:00
Gleb Smirnoff
2ee9b44cae Fix build with gcc. Move sf_buf_alloc()/sf_buf_free() declarations
to MD headers.
2013-09-06 17:44:13 +00:00
Alan Cox
51321f7c31 Significantly reduce the cost, i.e., run time, of calls to madvise(...,
MADV_DONTNEED) and madvise(..., MADV_FREE).  Specifically, introduce a new
pmap function, pmap_advise(), that operates on a range of virtual addresses
within the specified pmap, allowing for a more efficient implementation of
MADV_DONTNEED and MADV_FREE.  Previously, the implementation of
MADV_DONTNEED and MADV_FREE relied on per-page pmap operations, such as
pmap_clear_reference().  Intuitively, the problem with this implementation
is that the pmap-level locks are acquired and released and the page table
traversed repeatedly, once for each resident page in the range
that was specified to madvise(2).  A more subtle flaw with the previous
implementation is that pmap_clear_reference() would clear the reference bit
on all mappings to the specified page, not just the mapping in the range
specified to madvise(2).

Since our malloc(3) makes heavy use of madvise(2), this change can have a
measureable impact.  For example, the system time for completing a parallel
"buildworld" on a 6-core amd64 machine was reduced by about 1.5% to 2.0%.

Note: This change only contains pmap_advise() implementations for a subset
of our supported architectures.  I will commit implementations for the
remaining architectures after further testing.  For now, a stub function is
sufficient because of the advisory nature of pmap_advise().

Discussed with: jeff, jhb, kib
Tested by:      pho (i386), marcel (ia64)
Sponsored by:   EMC / Isilon Storage Division
2013-08-29 15:49:05 +00:00
Konstantin Belousov
e68c64f0ba Revert r254501. Instead, reuse the type stability of the struct pmap
which is the part of struct vmspace, allocated from UMA_ZONE_NOFREE
zone.  Initialize the pmap lock in the vmspace zone init function, and
remove pmap lock initialization and destruction from pmap_pinit() and
pmap_release().

Suggested and reviewed by:	alc (previous version)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2013-08-22 18:12:24 +00:00
Konstantin Belousov
5944de8ecd Remove the deprecated VM_ALLOC_RETRY flag for the vm_page_grab(9).
The flag was mandatory since r209792, where vm_page_grab(9) was
changed to only support the alloc retry semantic.

Suggested and reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
2013-08-22 07:39:53 +00:00
Pawel Jakub Dawidek
417ffc66fa Add process descriptors support to the GENERIC kernel. It is already being
used by the tools in base systems and with sandboxing more and more tools
the usage should only increase.

Submitted by:	Mariusz Zaborski <oshogbo@FreeBSD.org>
Sponsored by:	Google Summer of Code 2013
MFC after:	1 month
2013-08-18 10:21:29 +00:00
Attilio Rao
c7aebda8a1 The soft and hard busy mechanism rely on the vm object lock to work.
Unify the 2 concept into a real, minimal, sxlock where the shared
acquisition represent the soft busy and the exclusive acquisition
represent the hard busy.
The old VPO_WANTED mechanism becames the hard-path for this new lock
and it becomes per-page rather than per-object.
The vm_object lock becames an interlock for this functionality:
it can be held in both read or write mode.
However, if the vm_object lock is held in read mode while acquiring
or releasing the busy state, the thread owner cannot make any
assumption on the busy state unless it is also busying it.

Also:
- Add a new flag to directly shared busy pages while vm_page_alloc
  and vm_page_grab are being executed.  This will be very helpful
  once these functions happen under a read object lock.
- Move the swapping sleep into its own per-object flag

The KPI is heavilly changed this is why the version is bumped.
It is very likely that some VM ports users will need to change
their own code.

Sponsored by:	EMC / Isilon storage division
Discussed with:	alc
Reviewed by:	jeff, kib
Tested by:	gavin, bapt (older version)
Tested by:	pho, scottl
2013-08-09 11:11:11 +00:00
Andriy Gapon
9ba0691bdd follow up to r254051
- update powerpc/GENERIC64 as well, suggested by mdf
- update comments so that they make sense after the change, suggested by
  jhb

X-MFC after:	never (change specific to head)
2013-08-09 08:11:09 +00:00
Konstantin Belousov
449c2e92c9 Split the pagequeues per NUMA domains, and split pageademon process
into threads each processing queue in a single domain.  The structure
of the pagedaemons and queues is kept intact, most of the changes come
from the need for code to find an owning page queue for given page,
calculated from the segment containing the page.

The tie between NUMA domain and pagedaemon thread/pagequeue split is
rather arbitrary, the multithreaded daemon could be allowed for the
single-domain machines, or one domain might be split into several page
domains, to further increase concurrency.

Right now, each pagedaemon thread tries to reach the global target,
precalculated at the start of the pass.  This is not optimal, since it
could cause excessive page deactivation and freeing.  The code should
be changed to re-check the global page deficit state in the loop after
some number of iterations.

The pagedaemons reach the quorum before starting the OOM, since one
thread inability to meet the target is normal for split queues.  Only
when all pagedaemons fail to produce enough reusable pages, OOM is
started by single selected thread.

Launder is modified to take into account the segments layout with
regard to the region for which cleaning is performed.

Based on the preliminary patch by jeff, sponsored by EMC / Isilon
Storage Division.

Reviewed by:	alc
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2013-08-07 16:36:38 +00:00
Andriy Gapon
818d282e7b enable KDB_TRACE in GENERICs
KDB_TRACE is not an alternative to DDB/etc, they are complementary.
So I do not see any reason to not enable KDB_TRACE by default.

X-MFC after:	never (change specific to head)
2013-08-07 08:03:50 +00:00
Jeff Roberson
5df87b21d3 Replace kernel virtual address space allocation with vmem. This provides
transparent layering and better fragmentation.

 - Normalize functions that allocate memory to use kmem_*
 - Those that allocate address space are named kva_*
 - Those that operate on maps are named kmap_*
 - Implement recursive allocation handling for kmem_arena in vmem.

Reviewed by:	alc
Tested by:	pho
Sponsored by:	EMC / Isilon Storage Division
2013-08-07 06:21:20 +00:00
Marius Strobl
4af8466d8b Add MD (for now) atomic_store_acq_<type>() and use it in pmap_activate()
to get the semantics when setting the PMAP right. Prior to r251782, the
latter already used implicit acquire semantics, which - currently - means
to not employ additional explicit memory barriers under the hood (see also
r225889).
2013-08-06 15:34:11 +00:00
Attilio Rao
66bacd7e17 Remove unused member.
Sponsored by:	EMC / Isilon storage division
Reviewed by:	alc
Tested by:	pho
2013-08-04 21:17:05 +00:00
David E. O'Brien
0e6a0799a9 Back out r253779 & r253786. 2013-07-31 17:21:18 +00:00
David E. O'Brien
99ff83da74 Decouple yarrow from random(4) device.
* Make Yarrow an optional kernel component -- enabled by "YARROW_RNG" option.
  The files sha2.c, hash.c, randomdev_soft.c and yarrow.c comprise yarrow.

* random(4) device doesn't really depend on rijndael-*.  Yarrow, however, does.

* Add random_adaptors.[ch] which is basically a store of random_adaptor's.
  random_adaptor is basically an adapter that plugs in to random(4).
  random_adaptor can only be plugged in to random(4) very early in bootup.
  Unplugging random_adaptor from random(4) is not supported, and is probably a
  bad idea anyway, due to potential loss of entropy pools.
  We currently have 3 random_adaptors:
  + yarrow
  + rdrand (ivy.c)
  + nehemeiah

* Remove platform dependent logic from probe.c, and move it into
  corresponding registration routines of each random_adaptor provider.
  probe.c doesn't do anything other than picking a specific random_adaptor
  from a list of registered ones.

* If the kernel doesn't have any random_adaptor adapters present then the
  creation of /dev/random is postponed until next random_adaptor is kldload'ed.

* Fix randomdev_soft.c to refer to its own random_adaptor, instead of a
  system wide one.

Submitted by: arthurmesh@gmail.com, obrien
Obtained from: Juniper Networks
Reviewed by: obrien
2013-07-29 20:26:27 +00:00
Andriy Gapon
a29cc9a34b Revert r253748,253749
This WIP should not have been committed yet.

Pointyhat to:	avg
2013-07-28 18:44:17 +00:00
Andriy Gapon
366d8bfb7b put contents of cpu.h under _KERNEL
no userland-serviceable parts inside

MFC after:	20 days
2013-07-28 18:32:27 +00:00
Andrey V. Elsukov
dbd4437b06 Include sys/systm.h after sys/param.h.
Suggested by:	pluknet
2013-07-15 15:40:57 +00:00
Andrey V. Elsukov
05d1f5bce0 Introduce new structure sfstat for collecting sendfile's statistics
and remove corresponding fields from struct mbstat. Use PCPU counters
and SFSTAT_INC() macro for update these statistics.

Discussed with:	glebius
2013-07-15 06:16:57 +00:00
Marius Strobl
85338755c1 Prefix the alias macros for members of struct __mcontext with an underscore
in order to avoid a clash in the net80211 code.
2013-07-12 14:24:52 +00:00
Konstantin Belousov
70a7dd5d5b Fix issues with zeroing and fetching the counters, on x86 and ppc64.
Issues were noted by Bruce Evans and are present on all architectures.

On i386, a counter fetch should use atomic read of 64bit value,
otherwise carry from the increment on other CPU could be lost for the
given fetch, making error of 2^32.  If 64bit read (cmpxchg8b) is not
available on the machine, it cannot be SMP and it is enough to disable
preemption around read to avoid the split read.

On x86 the counter increment is not atomic on purpose, which makes it
possible for the store of the incremented result to override just
zeroed per-cpu slot.  The effect would be a counter going off by
arbitrary value after zeroing.  Perform the counter zeroing on the
same processor which does the increments, making the operations
mutually exclusive.  On i386, same as for the fetching, if the
cmpxchg8b is not available, machine is not SMP and we disable
preemption for zeroing.

PowerPC64 is treated the same as amd64.

For other architectures, the changes made to allow the compilation to
succeed, without fixing the issues with zeroing or fetching.  It
should be possible to handle them by using the 64bit loads and stores
atomic WRT preemption (assuming the architectures also converted from
using critical sections to proper asm).  If architecture does not
provide the facility, using global (spin) mutex would be non-optimal
but working solution.

Noted by:  bde
Sponsored by:	The FreeBSD Foundation
2013-07-01 02:48:27 +00:00
Ed Schouten
eaa3b76d1a Remove conflicting macros from SPARC64's atomic(9) header.
The atomic_load() and atomic_store() macros conflict with the equally
named macros from <stdatomic.h>. Remove them, as they are only used to
implement functions that are not present on any of the other
architectures.
2013-06-15 08:23:53 +00:00
Ed Schouten
1f7e35dce5 Stick to using the documented atomic(9) API.
The atomic_store_ptr() function is not part of the atomic(9) API. We
only provide a version with a release barrier.
2013-06-15 08:21:54 +00:00
Jeff Roberson
17a2737732 - Add a BIT_FFS() macro and use it to replace cpusetffs_obj()
Discussed with:	attilio
Sponsored by:	EMC / Isilon Storage Division
2013-06-13 20:46:03 +00:00
Attilio Rao
9af6d512f5 o Relax locking assertions for vm_page_find_least()
o Relax locking assertions for pmap_enter_object() and add them also
  to architectures that currently don't have any
o Introduce VM_OBJECT_LOCK_DOWNGRADE() which is basically a downgrade
  operation on the per-object rwlock
o Use all the mechanisms above to make vm_map_pmap_enter() to work
  mostl of the times only with readlocks.

Sponsored by:	EMC / Isilon storage division
Reviewed by:	alc
2013-05-21 20:38:19 +00:00
Alan Cox
658f180b3b Relax the object locking assertion in pmap_enter_locked().
Reviewed by:	attilio
Sponsored by:	EMC / Isilon Storage Division
2013-05-17 18:59:00 +00:00
Peter Wemm
dda759d344 Tidy up some CVS workarounds. 2013-05-12 01:53:47 +00:00
Attilio Rao
941646f5ec Rename VM_NDOMAIN into MAXMEMDOM and move it into machine/param.h in
order to match the MAXCPU concept.  The change should also be useful
for consolidation and consistency.

Sponsored by:	EMC / Isilon storage division
Obtained from:	jeff
Reviewed by:	alc
2013-05-07 22:46:24 +00:00
Edward Tomasz Napierala
8ed9860914 Remove ctl(4) from GENERIC. Also remove 'options CTL_DISABLE'
and kern.cam.ctl.disable tunable; those were introduced as a workaround
to make it possible to boot GENERIC on low memory machines.

With ctl(4) being built as a module and automatically loaded by ctladm(8),
this makes CTL work out of the box.

Reviewed by:	ken
Sponsored by:	FreeBSD Foundation
2013-04-12 16:25:03 +00:00
Gleb Smirnoff
4e76af6a41 Merge from projects/counters: counter(9).
Introduce counter(9) API, that implements fast and raceless counters,
provided (but not limited to) for gathering of statistical data.

See http://lists.freebsd.org/pipermail/freebsd-arch/2013-April/014204.html
for more details.

In collaboration with:	kib
Reviewed by:		luigi
Tested by:		ae, ray
Sponsored by:		Nginx, Inc.
2013-04-08 19:40:53 +00:00
Gleb Smirnoff
17dece86fe Merge from projects/counters:
Pad struct pcpu so that its size is denominator of PAGE_SIZE. This
is done to reduce memory waste in UMA_PCPU_ZONE zones.

Sponsored by:	Nginx, Inc.
2013-04-08 19:19:10 +00:00
Alexander Motin
45f6d66569 Remove all legacy ATA code parts, not used since options ATA_CAM enabled in
most kernels before FreeBSD 9.0.  Remove such modules and respective kernel
options: atadisk, ataraid, atapicd, atapifd, atapist, atapicam.  Remove the
atacontrol utility and some man pages.  Remove useless now options ATA_CAM.

No objections:	current@, stable@
MFC after:	never
2013-04-04 07:12:24 +00:00
Ian Lepore
4d7abca057 Fix low-level uart drivers that set their fifo sizes in the softc too late.
uart(4) allocates send and receiver buffers in attach() before it calls
the low-level driver's attach routine.  Many low-level drivers set the
fifo sizes in their attach routine, which is too late.  Other drivers set
them in the probe() routine, so that they're available when uart(4)
allocates buffers.  This fixes the ones that were setting the values too
late by moving the code to probe().
2013-04-01 00:44:20 +00:00
Konstantin Belousov
ee75e7de7b Implement the concept of the unmapped VMIO buffers, i.e. buffers which
do not map the b_pages pages into buffer_map KVA.  The use of the
unmapped buffers eliminate the need to perform TLB shootdown for
mapping on the buffer creation and reuse, greatly reducing the amount
of IPIs for shootdown on big-SMP machines and eliminating up to 25-30%
of the system time on i/o intensive workloads.

The unmapped buffer should be explicitely requested by the GB_UNMAPPED
flag by the consumer.  For unmapped buffer, no KVA reservation is
performed at all. The consumer might request unmapped buffer which
does have a KVA reserve, to manually map it without recursing into
buffer cache and blocking, with the GB_KVAALLOC flag.

When the mapped buffer is requested and unmapped buffer already
exists, the cache performs an upgrade, possibly reusing the KVA
reservation.

Unmapped buffer is translated into unmapped bio in g_vfs_strategy().
Unmapped bio carry a pointer to the vm_page_t array, offset and length
instead of the data pointer.  The provider which processes the bio
should explicitely specify a readiness to accept unmapped bio,
otherwise g_down geom thread performs the transient upgrade of the bio
request by mapping the pages into the new bio_transient_map KVA
submap.

The bio_transient_map submap claims up to 10% of the buffer map, and
the total buffer_map + bio_transient_map KVA usage stays the
same. Still, it could be manually tuned by kern.bio_transient_maxcnt
tunable, in the units of the transient mappings.  Eventually, the
bio_transient_map could be removed after all geom classes and drivers
can accept unmapped i/o requests.

Unmapped support can be turned off by the vfs.unmapped_buf_allowed
tunable, disabling which makes the buffer (or cluster) creation
requests to ignore GB_UNMAPPED and GB_KVAALLOC flags.  Unmapped
buffers are only enabled by default on the architectures where
pmap_copy_page() was implemented and tested.

In the rework, filesystem metadata is not the subject to maxbufspace
limit anymore. Since the metadata buffers are always mapped, the
buffers still have to fit into the buffer map, which provides a
reasonable (but practically unreachable) upper bound on it. The
non-metadata buffer allocations, both mapped and unmapped, is
accounted against maxbufspace, as before. Effectively, this means that
the maxbufspace is forced on mapped and unmapped buffers separately.
The pre-patch bufspace limiting code did not worked, because
buffer_map fragmentation does not allow the limit to be reached.

By Jeff Roberson request, the getnewbuf() function was split into
smaller single-purpose functions.

Sponsored by:	The FreeBSD Foundation
Discussed with:	jeff (previous version)
Tested by:	pho, scottl (previous version), jhb, bf
MFC after:	2 weeks
2013-03-19 14:13:12 +00:00
Konstantin Belousov
e8a4a618cf Add pmap function pmap_copy_pages(), which copies the content of the
pages around, taking array of vm_page_t both for source and
destination.  Starting offsets and total transfer size are specified.

The function implements optimal algorithm for copying using the
platform-specific optimizations.  For instance, on the architectures
were the direct map is available, no transient mappings are created,
for i386 the per-cpu ephemeral page frame is used.  The code was
typically borrowed from the pmap_copy_page() for the same
architecture.

Only i386/amd64, powerpc aim and arm/arm-v6 implementations were
tested at the time of commit. High-level code, not committed yet to
the tree, ensures that the use of the function is only allowed after
explicit enablement.

For sparc64, the existing code has known issues and a stab is added
instead, to allow the kernel linking.

Sponsored by:	The FreeBSD Foundation
Tested by:	pho (i386, amd64), scottl (amd64), ian (arm and arm-v6)
MFC after:	2 weeks
2013-03-14 20:18:12 +00:00
Attilio Rao
89f6b8632c Switch the vm_object mutex to be a rwlock. This will enable in the
future further optimizations where the vm_object lock will be held
in read mode most of the time the page cache resident pool of pages
are accessed for reading purposes.

The change is mostly mechanical but few notes are reported:
* The KPI changes as follow:
  - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK()
  - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK()
  - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK()
  - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED()
    (in order to avoid visibility of implementation details)
  - The read-mode operations are added:
    VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(),
    VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED()
* The vm/vm_pager.h namespace pollution avoidance (forcing requiring
  sys/mutex.h in consumers directly to cater its inlining functions
  using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h
  consumers now must include also sys/rwlock.h.
* zfs requires a quite convoluted fix to include FreeBSD rwlocks into
  the compat layer because the name clash between FreeBSD and solaris
  versions must be avoided.
  At this purpose zfs redefines the vm_object locking functions
  directly, isolating the FreeBSD components in specific compat stubs.

The KPI results heavilly broken by this commit.  Thirdy part ports must
be updated accordingly (I can think off-hand of VirtualBox, for example).

Sponsored by:	EMC / Isilon storage division
Reviewed by:	jeff
Reviewed by:	pjd (ZFS specific review)
Discussed with:	alc
Tested by:	pho
2013-03-09 02:32:23 +00:00
Marius Strobl
105421ff81 Merge r247814 from x86 modulo whitespace bug:
Turn on the CTL disable tunable by default.

This will allow GENERIC configurations to boot on small memory boxes, but
not require end users who want to use CTL to recompile their kernel.  They
can simply set kern.cam.ctl.disable=0 in loader.conf.
2013-03-08 13:11:45 +00:00
Gavin Atkinson
9ec80eff4c Correct two spelling mistakes in a comment. 2013-03-07 13:24:49 +00:00
Marius Strobl
e8aabc79db - Revert the part of r247601 which turned the overtemperature and power fail
interrupt shutdown handlers into filters. Shutdown_nice(9) acquires a sleep
  lock, which filters shouldn't do. It also seems that kern_reboot(9) still
  may require Giant to be hold.
- Correct an incorrect argument to shutdown_nice(9).

Submitted by:	bde
2013-03-02 13:08:13 +00:00
Marius Strobl
562799bb30 Revert the part of r247600 which turned the overtemperature and power fail
interrupt shutdown handlers into filters. Shutdown_nice(9) acquires a sleep
lock, which filters shouldn't do. It also seems that kern_reboot(9) still
may require Giant to be hold.

Submitted by:	bde
2013-03-02 13:04:58 +00:00
Marius Strobl
11be09b056 - Apparently, it's no longer a problem to call shutdown_nice(9) from within
an interrupt filter (some other drivers in the tree do the same). So
  change the overtemperature and power fail interrupts from handlers in order
  to code and get rid of a !INTR_MPSAFE handlers.
- Mark unused parameters as such.
- Use NULL instead of 0 for pointers.

MFC after:	1 week
2013-03-02 00:41:51 +00:00
Marius Strobl
7e026d15d5 - While Netra X1 generally show no ill effects when registering a power
fail interrupt handler, there seems to be either a broken batch of them
  or a tendency to develop a defect which causes this interrupt to fire
  inadvertedly. Given that apart from this problem these machines work
  just fine, add a tunable allowing the setup of the power fail interrupt
  to be disabled.
  While at it, remove the DEBUGGER_ON_POWERFAIL compile time option and
  make that behavior also selectable via the newly added tunable.
- Apparently, it's no longer a problem to call shutdown_nice(9) from within
  an interrupt filter (some other drivers in the tree do the same). So
  change the power fail interrupt from an handler in order to simplify the
  code and get rid of a !INTR_MPSAFE handler.
- Use NULL instead of 0 for pointers.

MFC after:	1 week
2013-03-02 00:37:31 +00:00
Marius Strobl
22f19117ed - In sbbc_pci_attach() just pass the already obtained bus tag and handle
instead of acquiring these anew.
- Use NULL instead of 0 for pointers.

MFC after:	1 week
2013-03-01 20:36:59 +00:00
Marius Strobl
1a5a52f1f9 - Remove an unused header.
- Use NULL instead of 0 for pointers.
- Let ofw_pcib_probe() return BUS_PROBE_DEFAULT instead of 0 so specialized
  PCI-PCI-bridge drivers may attach instead.
- Add WARs for PLX Technology PEX 8114 bridges and PEX 8532 switches.
  Ideally, these should live in MI code but at least for the latter we're
  missing the necessary infrastructure there.

MFC after:	1 week
2013-03-01 20:34:02 +00:00
Alexander Motin
fdc5dd2d2f MFcalloutng:
Switch eventtimers(9) from using struct bintime to sbintime_t.
Even before this not a single driver really supported full dynamic range of
struct bintime even in theory, not speaking about practical inexpediency.
This change legitimates the status quo and cleans up the code.
2013-02-28 13:46:03 +00:00
Attilio Rao
dc1558d1cd Merge from vmobj-rwlock:
VM_OBJECT_LOCKED() macro is only used to implement a custom version
of lock assertions right now (which likely spread out thanks to
copy and paste).
Remove it and implement actual assertions.

Sponsored by:	EMC / Isilon storage division
Reviewed by:	alc
Tested by:	pho
2013-02-27 18:12:13 +00:00
Attilio Rao
590f9303e5 Merge from vmobj-rwlock branch:
Remove unused inclusion of vm/vm_pager.h and vm/vnode_pager.h.

Sponsored by:	EMC / Isilon storage division
Tested by:	pho
Reviewed by:	alc
2013-02-26 01:00:11 +00:00
Konstantin Belousov
dd0b4fb6d5 Reform the busdma API so that new types may be added without modifying
every architecture's busdma_machdep.c.  It is done by unifying the
bus_dmamap_load_buffer() routines so that they may be called from MI
code.  The MD busdma is then given a chance to do any final processing
in the complete() callback.

The cam changes unify the bus_dmamap_load* handling in cam drivers.

The arm and mips implementations are updated to track virtual
addresses for sync().  Previously this was done in a type specific
way.  Now it is done in a generic way by recording the list of
virtuals in the map.

Submitted by:	jeff (sponsored by EMC/Isilon)
Reviewed by:	kan (previous version), scottl,
	mjacob (isp(4), no objections for target mode changes)
Discussed with:	     ian (arm changes)
Tested by:	marius (sparc64), mips (jmallet), isci(4) on x86 (jharris),
	amd64 (Fabian Keil <freebsd-listen@fabiankeil.de>)
2013-02-12 16:57:20 +00:00
Konstantin Belousov
00efd852cc The 'end' word was missed in the comment.
MFC after:     3 days
2013-02-08 15:52:20 +00:00
Eitan Adler
4752ed3d7f Remove support for plip from the GENERIC kernel as no systems in the
last 10 years require this support.

Discussed with:	db
Discussed with:	kib
Reviewed by:	imp
Reviewed by:	jhb
Reviewed by:	-hackers
Approved by:	cperciva (mentor)
2013-02-01 20:17:11 +00:00
Marius Strobl
718c2b5b11 Revert the part of r239864 which removed obtaining the SMP mutex around
reading registers from other CPUs. As it turns out, the hardware doesn't
really like concurrent IPI'ing causing adverse effects. Also the thought
deadlock when using this spin lock here and the targeted CPU(s) are also
holding or in case of nested locks can't actually happen. This is due to
the fact that on sparc64, spinlock_enter() only raises the PIL but doesn't
disable interrupts completely. Thus direct cross calls as used for the
register reading (and all other MD IPI needs) still will be executed by
the targeted CPU(s) in that case.

MFC after:	3 days
2013-01-23 22:52:20 +00:00