1661 Commits

Author SHA1 Message Date
jhibbits
c55aa7292d Fix the resource_list_print_type() calls to use uintmax_t.
Missed a bunch from r297000.
2016-03-22 22:25:08 +00:00
jhibbits
31bb8ee5bd Convert rman to use rman_res_t instead of u_long
Summary:
Migrate to using the semi-opaque type rman_res_t to specify rman resources.  For
now, this is still compatible with u_long.

This is step one in migrating rman to use uintmax_t for resources instead of
u_long.

Going forward, this could feasibly be used to specify architecture-specific
definitions of resource ranges, rather than baking a specific integer type into
the API.

This change has been broken out to facilitate MFC'ing drivers back to 10 without
breaking ABI.

Reviewed By: jhb
Sponsored by:	Alex Perez/Inertial Computing
Differential Revision: https://reviews.freebsd.org/D5075
2016-01-27 02:23:54 +00:00
emaste
1ba5532df7 Fix kernel build ${MACHINE} path
$M should be the kernel machine src directory, ${MACHINE}. In most cases
${MACHINE} and ${MACHINE_CPUARCH} are the same, but this is not true for
pc98 and arm64.

It appears we previously set M=${MACHINE_CPUARCH} as a workaround to
accommodate pc98, where MACHINE_CPUARCH is pc98 but it uses
sys/i386/i386/genassym.c.

arm64 relies on this being set correctly, so update $M and add explicit
workarounds for pc98.

Differential Revision:	https://reviews.freebsd.org/D2307
Reviewed by:	andrew, imp
Sponsored by:	The FreeBSD Foundation
2015-04-16 22:34:10 +00:00
nyan
c8db1036c4 Merge pc98's machdep.c into i386/i386/machdep.c. 2014-10-04 06:01:30 +00:00
royger
494dc32ba6 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
jhb
fa53fae9e4 MFamd64: Use initializecpu() to set various model-specific registers on
AP startup and AP resume (it was already used for BSP startup and BSP
resume).
- Split code to do one-time probing of cache properties out of
  initializecpu() and into initializecpucache().  This is called once on
  the BSP during boot.
- Move enable_sse() into initializecpu().
- Call initializecpu() for AP startup instead of enable_sse() and
  manually frobbing MSR_EFER to enable PG_NX.
- Call initializecpu() when an AP resumes.  In theory this will now
  properly re-enable PG_NX in MSR_EFER when resuming a PAE kernel on
  APs.
2014-09-10 21:37:47 +00:00
jhb
1e7d9a1324 - Move prototypes for various functions into out of C files and into
<machine/md_var.h>.
- Move some CPU-related variables out of i386/i386/identcpu.c to
  initcpu.c to match amd64.
- Move the declaration of has_f00f_hack out of identcpu.c to machdep.c.
- Remove a misleading comment from i386/i386/initcpu.c (locore zeros
  the BSS before it calls identify_cpu()) and remove explicit zero
  assignments to reduce the diff with amd64.
2014-09-04 01:46:06 +00:00
hselasky
c676f789a4 Compile fixes:
Remove duplicate "debug_ktr.mask" sysctl definition.
Remove now unused variable from "kern_ktr.c".
This fixes build of "ktr" which was broken by r267961.

Let the default value for "vm_kmem_size_scale" be zero. It is setup
after that the sysctl has been initialized from "getenv()" in the
"kmeminit()" function to equal the "VM_KMEM_SIZE_MAX" value, if
zero. On Sparc64 the "VM_KMEM_SIZE_MAX" macro is not a constant. This
fixes build of Sparc64 which was broken by r267961.

Add a special macro to dynamically create SYSCTL root nodes, because
root nodes have a special parent. This fixes build of existing OFED
module and CANBUS module for pc98 which was broken by r267961.

Add missing "sysctl.h" includes to get the needed sysctl header file
declarations. This is needed after r267961.

MFC after:	2 weeks
2014-06-28 17:36:18 +00:00
hselasky
35b126e324 Pull in r267961 and r267973 again. Fix for issues reported will follow. 2014-06-28 03:56:17 +00:00
gjb
fc21f40567 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
hselasky
bd1ed65f0f 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
nyan
37c4ec75f2 MFi386: r257858 (by kib)
Fix signal delivery for the iBCS2 binaries.
2014-04-20 05:40:13 +00:00
bdrewery
6fcf6199a4 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
glebius
80e85e32a5 Remove AppleTalk support.
AppleTalk was a network transport protocol for Apple Macintosh devices
in 80s and then 90s. Starting with Mac OS X in 2000 the AppleTalk was
a legacy protocol and primary networking protocol is TCP/IP. The last
Mac OS X release to support AppleTalk happened in 2009. The same year
routing equipment vendors (namely Cisco) end their support.

Thus, AppleTalk won't be supported in FreeBSD 11.0-RELEASE.
2014-03-14 06:29:43 +00:00
glebius
d494babace Remove IPX support.
IPX was a network transport protocol in Novell's NetWare network operating
system from late 80s and then 90s. The NetWare itself switched to TCP/IP
as default transport in 1998. Later, in this century the Novell Open
Enterprise Server became successor of Novell NetWare. The last release
that claimed to still support IPX was OES 2 in 2007. Routing equipment
vendors (e.g. Cisco) discontinued support for IPX in 2011.

Thus, IPX won't be supported in FreeBSD 11.0-RELEASE.
2014-03-14 02:58:48 +00:00
royger
467e743960 xen: implement an early timer for Xen PVH
When running as a PVH guest, there's no emulated i8254, so we need to
use the Xen PV timer as the early source for DELAY. This change allows
for different implementations of the early DELAY function and
implements a Xen variant for it.

Approved by: gibbs
Sponsored by: Citrix Systems R&D

dev/xen/timer/timer.c:
dev/xen/timer/timer.h:
 - Implement Xen early delay functions using the PV timer and declare
   them.

x86/include/init.h:
 - Add hooks for early clock source initialization and early delay
   functions.

i386/i386/machdep.c:
pc98/pc98/machdep.c:
amd64/amd64/machdep.c:
 - Set early delay hooks to use the i8254 on bare metal.
 - Use clock_init (that will in turn make use of init_ops) to
   initialize the early clock source.

amd64/include/clock.h:
i386/include/clock.h:
 - Declare i8254_delay and clock_init.

i386/xen/clock.c:
 - Rename DELAY to i8254_delay.

x86/isa/clock.c:
 - Introduce clock_init that will take care of initializing the early
   clock by making use of the init_ops hooks.
 - Move non ISA related delay functions to the newly introduced delay
   file.

x86/x86/delay.c:
 - Add moved delay related functions.
 - Implement generic DELAY function that will use the init_ops hooks.

x86/xen/pv.c:
 - Set PVH hooks for the early delay related functions in init_ops.

conf/files.amd64:
conf/files.i386:
conf/files.pc98:
 - Add delay.c to the kernel build.
2014-03-11 10:20:42 +00:00
jhb
22ac1edc7b Don't waste a page of KVA for the boot-time memory test on x86. For amd64,
reuse the first page of the crashdumpmap as CMAP1/CADDR1.  For i386,
remove CMAP1/CADDR1 entirely and reuse CMAP3/CADDR3 for the memory test.

Reviewed by:	alc, peter
MFC after:	2 weeks
2014-02-11 22:02:40 +00:00
jhb
b2533ec507 Move <machine/apicvar.h> to <x86/apicvar.h>. 2014-01-23 20:10:22 +00:00
jhb
0f5dd6ee19 Fix a typo. 2013-12-05 21:58:02 +00:00
attilio
7ee4e910ce - For kernel compiled only with KDTRACE_HOOKS and not any lock debugging
option, unbreak the lock tracing release semantic by embedding
  calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
  version of the releasing functions for mutex, rwlock and sxlock.
  Failing to do so skips the lockstat_probe_func invokation for
  unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
  kernel compiled without lock debugging options, potentially every
  consumer must be compiled including opt_kdtrace.h.
  Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
  dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
  is linked there and it is only used as a compile-time stub [0].

[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested.  As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while.  Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].

Sponsored by:	EMC / Isilon storage division
Discussed with:	rstone
[0] Reported by:	rstone
[1] Discussed with:	philip
2013-11-25 07:38:45 +00:00
emaste
9dcbb8e88d x86: Allow users to change PSL_RF via ptrace(PT_SETREGS...)
Debuggers may need to change PSL_RF.  Note that tf_eflags is already stored
in the signal context during signal handling and PSL_RF previously could be
modified via sigreturn, so this change should not provide any new ability
to userspace.

For background see the thread at:
http://lists.freebsd.org/pipermail/freebsd-i386/2007-September/005910.html

Reviewed by:	jhb, kib
Sponsored by:	DARPA, AFRL
2013-11-14 15:37:20 +00:00
jkim
28a0f6da76 MFi386: r254619
Reimplement atomic_load_acq_64() and atomic_store_rel_64() for i386.

Noticed by:	tinderbox
2013-08-22 16:39:59 +00:00
jeff
de4ecca213 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
nyan
6a699f9f06 MFi386: revision 251039
Use slightly more idiomatic expression to get the address of array.
2013-06-01 12:21:59 +00:00
gabor
301f6461b7 - Correct mispellings of word resource
Submitted by:	Christoph Mallon <christoph.mallon@gmx.de>
2013-04-17 11:47:32 +00:00
attilio
e98f58faf6 MFC 2013-03-02 14:48:41 +00:00
davide
2bf12d0c7c MFcalloutng:
When CPU becomes idle, cpu_idleclock() calculates time to the next timer
event in order to reprogram hw timer. Return that time in sbintime_t to
the caller and pass it to acpi_cpu_idle(), where it can be used as one
more factor (quite precise) to extimate furter sleep time and choose
optimal sleep state. This is a preparatory change for further callout
improvements will be committed in the next days.

The commmit is not targeted for MFC.
2013-02-28 10:46:54 +00:00
attilio
066bbc97b6 Fix other architectures and ZFS.
Sponsored by:	EMC / Isilon storage division
2013-02-21 15:02:36 +00:00
nyan
beb4c4db63 Reduce diffs against i386. 2012-11-10 13:48:41 +00:00
nyan
8cda8e16a3 Fix some KASSERTs.
They are missing changes from r208833, r227394 and r227442.
2012-11-10 13:41:25 +00:00
nyan
d6f477073b MFi386: r211924
Register an interrupt vector for DTrace return probes.
2012-11-10 13:25:46 +00:00
eadler
f3db91bee2 The 'testing memory' patch gets printed too many times
Approved by: cperciva (implicit)
2012-10-22 11:57:26 +00:00
eadler
0b45640988 Explain the upcoming delay by printing a message when the kernel
is about to begin testing memory.

Reviewed by:	dteske, adri
Approved by:	cperciva
MFC after:	1 week
2012-10-22 03:16:39 +00:00
attilio
3212891c92 Reverts r234074,234105,234564,234723,234989,235231-235232 and part of
r234247.
Use, instead, the static intializer introduced in r239923 for x86 and
sparc64 intr_cpus, unwinding the code to the initial version.

Reviewed by:	marius
2012-10-09 12:22:43 +00:00
nyan
12e520c063 MFi386: revision 237445
Commit changes missed from r237435.  Properly calculate the signal
  trampoline addresses after the shared page is enabled.  Handle FreeBSD
  ABIs without shared page support too.

MFi386: revision 238792

  Introduce curpcb magic variable.
2012-09-23 09:13:57 +00:00
jhb
fb20c6fee6 Partially revert r217515 so that the mem_range_softc variable is always
present on x86 kernels.  This fixes the build of kernels that include
'device acpi' but do not include 'device mem'.

MFC after:	1 month
2012-07-09 20:42:08 +00:00
iwasaki
31eddd58e3 Add SMP/i386 suspend/resume support.
Most part is merged from amd64.

- i386/acpica/acpi_wakecode.S
Replaced with amd64 code (from realmode to paging enabling code).

- i386/acpica/acpi_wakeup.c
Replaced with amd64 code (except for wakeup_pagetables stuff).

- i386/include/pcb.h
- i386/i386/genassym.c
Added PCB new members (CR0, CR2, CR4, DS, ED, FS, SS, GDT, IDT, LDT
and TR) needed for suspend/resume, not for context switch.

- i386/i386/swtch.s
Added suspendctx() and resumectx().
Note that savectx() was not changed and used for suspending (while
amd64 code uses it).
BSP and AP execute the same sequence, suspendctx(), acpi_wakecode()
and resumectx() for suspend/resume (in case of UP system also).

- i386/i386/apic_vector.s
Added cpususpend().

- i386/i386/mp_machdep.c
- i386/include/smp.h
Added cpususpend_handler().

- i386/include/apicvar.h
- kern/subr_smp.c
- sys/smp.h
Added IPI_SUSPEND and suspend_cpus().

- i386/i386/initcpu.c
- i386/i386/machdep.c
- i386/include/md_var.h
- pc98/pc98/machdep.c
Moved initializecpu() declarations to md_var.h.

MFC after:	3 days
2012-05-18 18:55:58 +00:00
attilio
0b98e6d835 Clean up the intr* MD KPI from the SMP dependency, removing a cause of
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
2012-04-26 20:24:25 +00:00
nyan
0b8dc3a5af MFi386: revisions 234074 and 234105
- Adding the BSP as an interrupt target directly in cpu_startup().
2012-04-22 04:36:25 +00:00
nyan
fbebe4e777 - Fix to build a native i386 kernel without the SMP and atpic.
- Merge r232744 changes to pc98.
  (Allow a kernel to be built with 'nodevice atpic'.)
- Move ICU related defines from x86/isa/atpic.c to x86/isa/icu.h and
  use them in x86/x86/intr_machdep.c.

Reviewed by:	jhb
2012-03-16 12:13:44 +00:00
kib
361bfae5c2 Add support for the extended FPU states on amd64, both for native
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
2012-01-21 17:45:27 +00:00
marius
0fa74f406f Move the scsi_da_bios_params() prototype from pc98_machdep.h to md_var.h
where the prototype for pc98_ata_disk_firmware_geom_adjust() also lives
in order to avoid an #ifdef'ed include in cam(4).
2011-11-27 16:22:19 +00:00
nyan
2d080ae31f MFi386: revision 225936
Add some improvements in the idle table callbacks:
  - 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.
2011-10-04 13:24:22 +00:00
kmacy
99851f359e In order to maximize the re-usability of kernel code in user space this
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)
2011-09-16 13:58:51 +00:00
bz
422bc41b31 In HEAD when doing no further checkes there is no reason use the
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)
2011-08-20 19:21:46 +00:00
bz
632886e187 Introduce a tunable to disable the time consuming parts of bootup
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
2011-07-30 13:33:05 +00:00
avg
74204e61b2 remove code for dynamic offlining/onlining of CPUs on x86
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
2011-06-08 08:12:15 +00:00
jkim
218c7113ed Reinstate cpu_est_clockrate() support for P-state invariant TSC if APERF and
MPERF MSRs are available.  It was disabled in r216443.  Remove the earlier
hack to subtract 0.5% from the calibrated frequency as DELAY(9) is little
bit more reliable now.
2011-04-12 23:04:01 +00:00
jkim
95c723445e Use atomic load & store for TSC frequency. It may be overkill for amd64 but
safer for i386 because it can be easily over 4 GHz now.  More worse, it can
be easily changed by user with 'machdep.tsc_freq' tunable (directly) or
cpufreq(4) (indirectly).  Note it is intentionally not used in performance
critical paths to avoid performance regression (but we should, in theory).
Alternatively, we may add "virtual TSC" with lower frequency if maximum
frequency overflows 32 bits (and ignore possible incoherency as we do now).
2011-04-07 23:28:28 +00:00
jkim
0c7a0c810c Implement atomic_load_acq_64(9) and atomic_store_rel_64(9) for i386. These
functions are implemented with CMPXCHG8B instruction where it is available,
i. e., all Pentium-class and later processors.  Note this instruction is
also used for atomic_store_rel_64() because a simple XCHG-like instruction
for 64-bit memory access does not exist, unfortunately.  If the processor
lacks the instruction, i. e., 80486-class CPUs, two 32-bit load/store are
performed with interrupt temporarily disabled, assuming it does not support
SMP.  Although this assumption may be little naive, it is true in reality.
This implementation is inspired by Linux.
2011-04-06 23:59:59 +00:00