quad core 8 socket system will have apic id lifting.the apic id range could
be [4, 0x23]. and apic_is_clustered_box will think that need to three clusters
and that is larger than 2. So it is treated as a clustered_box.
and will get:
Marking TSC unstable due to TSCs unsynchronized
even if the CPUs have X86_FEATURE_CONSTANT_TSC set.
this quick fix will check if the cpu is from AMD.
but vsmp still needs that checking...
this patch is fix to make sure that vsmp not to be passed.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
when comparing the e820 direct from BIOS, and the one by kexec:
BIOS-provided physical RAM map:
- BIOS-e820: 0000000000000000 - 0000000000097400 (usable)
+ BIOS-e820: 0000000000000100 - 0000000000097400 (usable)
BIOS-e820: 0000000000097400 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000e6000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 00000000dffa0000 (usable)
- BIOS-e820: 00000000dffae000 - 00000000dffb0000 type 9
+ BIOS-e820: 00000000dffae000 - 00000000dffb0000 (reserved)
BIOS-e820: 00000000dffb0000 - 00000000dffbe000 (ACPI data)
BIOS-e820: 00000000dffbe000 - 00000000dfff0000 (ACPI NVS)
BIOS-e820: 00000000dfff0000 - 00000000e0000000 (reserved)
BIOS-e820: 00000000fec00000 - 00000000fec01000 (reserved)
- BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
=======> that is the local apic address... somewhere we lost it
BIOS-e820: 00000000ff700000 - 0000000100000000 (reserved)
BIOS-e820: 0000000100000000 - 0000004020000000 (usable)
found one entry about reserved is missing for the kernel by kexec.
it turns out init_apic_mappings is called before e820_reserve_resources
in setup_arch. but e820_reserve_resources is using request_resource.
it will not handle the conflicts.
there are three ways to fix it:
1. change request_resource in e820_reserve_resources to to insert_resource
2. move init_apic_mappings after e820_reserve_resources
3. use late_initcall to insert lapic resource.
this patch is using method 3, that is less intrusive.
in later version could consider to use method 1.
before patch
fed20000-ffffffff : PCI Bus #00
fee00000-fee00fff : Local APIC
fefff000-feffffff : pnp 00:09
ff700000-ffffffff : reserved
with patch will get map in first kernel
fed20000-ffffffff : PCI Bus #00
fee00000-fee00fff : Local APIC
fee00000-fee00fff : reserved
fefff000-feffffff : pnp 00:09
ff700000-ffffffff : reserved
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
e820_resource_resources could use insert_resource instead of request_resource
also move code_resource, data_resource, bss_resource, and crashk_res
out of e820_reserve_resources.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Copy x86_64 and add a head32.c so we can start moving early
architecture initialization out of assembly.
[ Sam Ravnborg <sam@ravnborg.org>: updated it to x86 ]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
quad core 8 socket system will have apic id lifting.the apic id range could
be [4, 0x23]. and apic_is_clustered_box will think that need to three clusters
and that is large than 2. So it is treated as clustered_box.
and will get
Marking TSC unstable due to TSCs unsynchronized
even the CPUs have X86_FEATURE_CONSTANT_TSC set.
this patch will check if the cpu is from AMD.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now cpu/proc.c and cpu/proc_64.c are same.
So cpu/proc_64.c can be removed.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Change /proc/cpuinfo on 32-bit, it will look like on 64-bit.
'power management' line is added and power management information
will be printed at the line.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86 /proc/cpuinfo code can be unified.
This is the first step of unification.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The patch fixes 33 errors and a few warnings reported by checkpatch.pl
arch/x86/oprofile/op_model_athlon.o:
text data bss dec hex filename
1691 0 32 1723 6bb op_model_athlon.o.before
1691 0 32 1723 6bb op_model_athlon.o.after
md5:
c354bc2d7140e1e626c03390eddaa0a6 op_model_athlon.o.before.asm
c354bc2d7140e1e626c03390eddaa0a6 op_model_athlon.o.after.asm
Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The patch make the file errors free.
Only 4 "WARNING: line over 80 characters" left.
arch/x86/kernel/cpu/mcheck/p5.o:
text data bss dec hex filename
452 0 4 456 1c8 p5.o.before
452 0 4 456 1c8 p5.o.after
md5:
50c945ef150aa95bf0481cc3e1dc3315 p5.o.before.asm
50c945ef150aa95bf0481cc3e1dc3315 p5.o.after.asm
Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The patch kills 45 errors and a few warnings.
The file is now error/warning free:
total: 0 errors, 0 warnings, 237 lines checked
arch/x86/lib/string_32.c has no obvious style problems and is ready for submission.
no code changed:
arch/x86/lib/string_32.o:
text data bss dec hex filename
639 0 0 639 27f string_32.o.before
639 0 0 639 27f string_32.o.after
md5:
2db1c48187cf5113bb595153ee1fc73d string_32.o.before.asm
2db1c48187cf5113bb595153ee1fc73d string_32.o.after.asm
Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Also update field names to simply payload_{offset,length} so as to not rule
out uncompressed images.
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
> Don't we have a special section for page-aligned data so it doesn't
> waste most of two pages?
We have .bss.page_aligned and it seems appropriate to use it.
text data bss dec hex filename
- 3388 8236 4 11628 2d6c ../build-32/arch/x86/mm/ioremap.o
+ 3388 48 4100 7536 1d70 ../build-32/arch/x86/mm/ioremap.o
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Kills more than 150 errors/warnings
Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
fix code to access CMOS rtc registers so that it does not use inb_p and
outb_p routines, which are deprecated. Extensive research on all known
CMOS RTC chipset timing shows that there is no need for a delay in
accessing the registers of these chips even on old machines. These chipa
are never on an expansion bus, but have always been "motherboard"
resources, either in the processor chipset or explicitly on the
motherboard, and they are not part of the ISA/LPC or PCI buses, so
delays should not be based on bus timing. The reason to fix it:
1) port 80 writes often hang some laptops that use ENE EC chipsets,
esp. those designed and manufactured by Quanta for HP;
2) RTC accesses are timing sensitive, and extra microseconds may matter;
3) the new "io_delay" function is calibrated by expansion bus timing needs,
thus is not appropriate for access to CMOS rtc registers.
Signed-off-by: David P. Reed <dpreed@reed.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Replace the hardcoded list of initialization functions for each CPU
vendor by a list in an ELF section, which is read at initialization in
arch/x86/kernel/cpu/cpu.c to fill the cpu_devs[] array. The ELF
section, named .x86cpuvendor.init, is reclaimed after boot, and
contains entries of type "struct cpu_vendor_dev" which associates a
vendor number with a pointer to a "struct cpu_dev" structure.
This first modification allows to remove all the VENDOR_init_cpu()
functions.
This patch also removes the hardcoded calls to early_init_amd() and
early_init_intel(). Instead, we add a "c_early_init" member to the
cpu_dev structure, which is then called if not NULL by the generic CPU
initialization code. Unfortunately, in early_cpu_detect(), this_cpu is
not yet set, so we have to use the cpu_devs[] array directly.
This patch is part of the Linux Tiny project, and is needed for
further patch that will allow to disable compilation of unused CPU
support code.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
It becomes to early for ioremap, so we use early_ioremap
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ravikiran Thirumalai <kiran@scalemp.com>
Acked-by: Shai Fultheim <shai@scalemp.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Change Makefile so vsmp_64.o object is dependent
on PARAVIRT, rather than X86_VSMP
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ravikiran Thirumalai <kiran@scalemp.com>
Acked-by: Shai Fultheim <shai@scalemp.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
we don't need get that so early.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
I found it strange that the struct sk_buff definition was found
inside the DWARF debugging sections in the generated object, so I verified
and found that there is no need for the files that bring struct sk_buff
definition into this file and verified also that sk_buff is not brought
in indirectly too, thru other headers.
I went on and removed many other unneeded includes and the end
result is:
[acme@doppio net-2.6]$ l /tmp/sys_ia32.o.before /tmp/sys_ia32.o.after
-rw-rw-r-- 1 acme acme 185240 2008-02-06 19:19 /tmp/sys_ia32.o.after
-rw-rw-r-- 1 acme acme 248328 2008-02-06 19:00 /tmp/sys_ia32.o.before
Almost 64KB only on this object file!
There were no other side effects from this change:
[acme@doppio net-2.6]$ objcopy -j "text" /tmp/sys_ia32.o.before /tmp/text.before
[acme@doppio net-2.6]$ objcopy -j "text" /tmp/sys_ia32.o.after /tmp/text.after
[acme@doppio net-2.6]$ md5sum /tmp/text.before /tmp/text.after
b7ac9b17942add68494e698e4f965d36 /tmp/text.before
b7ac9b17942add68494e698e4f965d36 /tmp/text.after
One of the complaints about using tools such as systemtap is
that one has to install the huge kernel-debuginfo package:
[acme@doppio net-2.6]$ rpm -q --qf "%{size}\n" kernel-rt-debuginfo
471737710
543867594
[acme@doppio net-2.6]$
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: virtualization@lists.linux-foundation.org
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[ tglx@linutronix.de: cleanup the other structs as well ]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The extended century readout does not solve the year 2038 problem on
32bit!
v2: Fix compilation on !ACPI, pointed out by tglx
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We assume that the RTC clock is BCD, so print a warning if it claims
to be binary.
[ tglx@linutronix.de: changed to WARN_ON - we want to know that!
If no one reports it we can remove the complete if (RTC_ALWAYS_BCD)
magic, which has RTC_ALWAYS_BCD defined to 1 since Linux 1.0 ... ]
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We know it is already after 2000. Use the year 2000 offset for both 32
and 64 bit, which removes ifdefs and the 1970 magic.
[ tglx@linutronix.de: remove 1970 magic, replace bogus commit message ]
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Change size to unsigned long, becase caller and user all used unsigned long.
Also make bad_addr take an alignment parameter.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The AMD Fam10h CPUs support new Gigabyte page table entry for
mapping 1GB at a time. Use this for the kernel direct mapping.
Only done for 64bit because i386 does not support GB page tables.
This only applies to the data portion of the direct mapping; the
kernel text mapping stays with 2MB pages because the AMD Fam10h
microarchitecture does not support GB ITLBs and AMD recommends
against using GB mappings for code.
Can be disabled with disable_gbpages on the kernel command line
[ tglx@linutronix.de: simplify enable code ]
[ Yinghai Lu <yinghai.lu@sun.com>: boot fix on 256 GB RAM ]
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
These new controls toggle experimental support for a new CPU feature,
the straightforward extension of largepages from the pmd level to the
pud level, which allows 1GB (kernel) TLBs instead of 2MB TLBs.
Turn it off by default, as this code has not been tested well enough yet.
Use the CONFIG_DIRECT_GBPAGES=y .config option or gbpages on the
boot line can be used to enable it. If enabled in the .config then
nogbpages boot option disables it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Clean up the page table dumper (fix boundary conditions, table driven
address ranges, some formatting changes since it is no longer using
the kernel log but a separate virtual file), and generalize to 32
bits.
[ mingo@elte.hu: x86: fix the pagetable dumper ]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch adds code to the kernel to have an (optional)
/proc/kernel_page_tables debug file that basically dumps the kernel
pagetables; this allows us kernel developers to verify that nothing fishy is
going on and that the various mappings are set up correctly. This was quite
useful in finding various change_page_attr() bugs, and is very likely to be
useful in the future as well.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: mingo@elte.hu
Cc: tglx@tglx.de
Cc: hpa@zytor.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Unify arch/x86/mm/Makefile between 32 and 64 bits.
All configuration variables that are protected by Kconfig constraints
have been put in the common part of the Makefile; however, the NUMA
files are totally different between 32 and 64 bits and are handled via
an ifdef.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add debug information for DEBUG_PAGEALLOC to get some statistics about
the pool usage and split status.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We map a VMA for the 32-bit vDSO even when it's disabled, which is stupid.
For the 32-bit kernel it's the vdso_enabled boot parameter/sysctl
and for the 64-bit kernel it's the vdso32 boot parameter/syscall32 sysctl.
When it's disabled, we don't pass AT_SYSINFO_EHDR so processes don't use
the vDSO for anything, but we still map it. For the non-compat vDSO,
this means we're always putting an extra VMA somewhere, maybe lousing
up the control of the address space the user was hoping for.
Honor the setting by doing nothing in arch_setup_additional_pages.
[ also see: "x86 vDSO: don't use disabled vDSO for signal trampoline" ]
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If the vDSO was not mapped, don't use it as the "restorer" for a signal
handler. Whether we have a pointer in mm->context.vdso depends on what
happened at exec time, so we shouldn't check any global flags now.
Background:
Currently, every 32-bit exec gets the vDSO mapped even if it's disabled
(the process just doesn't get told about it). Because it's in fact
always there, the bug that this patch fixes cannot happen now. With
the second patch, it won't be mapped at all when it's disabled, which is
one of the things that people might really want when they disable it (so
nothing they didn't ask for goes into their address space).
The 32-bit signal handler setup when SA_RESTORER is not used refers to
current->mm->context.vdso without regard to whether the vDSO has been
disabled when the process was exec'd. This patch fixes this not to use
it when it's null, which becomes possible after the second patch. (This
never happens in normal use, because glibc's sigaction call uses
SA_RESTORER unless glibc detected the vDSO.)
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
people sometimes do crazy stuff like building really large static
arrays into their kernels or building allyesconfig kernels. Give
more space to the kernel and push modules up a bit: kernel has
512 MB and modules have 1.5 GB.
Should be enough for a few years ;-)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
http://bugzilla.kernel.org/show_bug.cgi?id=10124
this change:
commit 08f1c192c3
Author: Muli Ben-Yehuda <muli@il.ibm.com>
Date: Sun Jul 22 00:23:39 2007 +0300
x86-64: introduce struct pci_sysdata to facilitate sharing of ->sysdata
This patch introduces struct pci_sysdata to x86 and x86-64, and
converts the existing two users (NUMA, Calgary) to use it.
This lays the groundwork for having other users of sysdata, such as
the PCI domains work.
The Calgary bits are tested, the NUMA bits just look ok.
replaces pcibios_scan_root by pci_scan_bus_parented...
but in pcibios_scan_root we have a check about scanned busses.
Cc: <yakui.zhao@intel.com>
Cc: Stian Jordet <stian@jordet.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Yinghai Lu" <yhlu.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The prevent_tail_call() macro works around the problem of the compiler
clobbering argument words on the stack, which for asmlinkage functions
is the caller's (user's) struct pt_regs. The tail/sibling-call
optimization is not the only way that the compiler can decide to use
stack argument words as scratch space, which we have to prevent.
Other optimizations can do it too.
Until we have new compiler support to make "asmlinkage" binding on the
compiler's own use of the stack argument frame, we have work around all
the manifestations of this issue that crop up.
More cases seem to be prevented by also keeping the incoming argument
variables live at the end of the function. This makes their original
stack slots attractive places to leave those variables, so the compiler
tends not clobber them for something else. It's still no guarantee, but
it handles some observed cases that prevent_tail_call() did not.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch also resolves hangs on boot:
http://lkml.org/lkml/2008/2/23/263http://bugzilla.kernel.org/show_bug.cgi?id=10093
The bug was causing once-in-few-reboots 10-15 sec wait during boot on
certain laptops.
Earlier commit 40d6a14662 added
smp_call_function in cpu_idle_wait() to kick cpus that are in tickless
idle. Looking at cpu_idle_wait code at that time, code seemed to be
over-engineered for a case which is rarely used (while changing idle
handler).
Below is a simplified version of cpu_idle_wait, which just makes a dummy
smp_call_function to all cpus, to make them come out of old idle handler
and start using the new idle handler. It eliminates code in the idle
loop to handle cpu_idle_wait.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
gcc expects all toplevel assembly to return to the original section type.
The code in alteranative.c does not do this. This caused some strange bugs
in sched-devel where code would end up in the .rodata section and when
the kernel sets the NX bit on all .rodata, the kernel would crash when
executing this code.
This patch adds a .previous marker to return the code back to the
original section.
Credit goes to Andrew Pinski for telling me it wasn't a gcc bug but a
bug in the toplevel asm code in the kernel. ;-)
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In time_cpufreq_notifier() the cpu id to act upon is held in freq->cpu. Use it
instead of smp_processor_id() in the call to set_cyc2ns_scale().
This makes the preempt_*able() unnecessary and lets set_cyc2ns_scale() update
the intended cpu's cyc2ns.
Related mail/thread: http://lkml.org/lkml/2007/12/7/130
Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
revert:
| commit 47001d6033
| Author: Thomas Gleixner <tglx@linutronix.de>
| Date: Tue Apr 1 19:45:18 2008 +0200
|
| x86: tsc prevent time going backwards
it has been identified to cause suspend regression - and the
commit fixes a longstanding bug that existed before 2.6.25 was
opened - so it can wait some more until the effects are better
understood.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We handle a broken tsc these days, so no need to panic. We clear the
TSC bit when tsc_init decides it's unreliable (eg. under lguest w/ bad
host TSC), leading to bogus panic.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The commits:
commit 37a47db8d7
Author: Balaji Rao <balajirrao@gmail.com>
Date: Wed Jan 30 13:30:03 2008 +0100
x86: assign IRQs to HPET timers, fix
and
commit e3f37a54f6
Author: Balaji Rao <balajirrao@gmail.com>
Date: Wed Jan 30 13:30:03 2008 +0100
x86: assign IRQs to HPET timers
have been identified to cause a regression on some platforms due to
the assignement of legacy IRQs which makes the legacy devices
connected to those IRQs disfunctional.
Revert them.
This fixes http://bugzilla.kernel.org/show_bug.cgi?id=10382
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We already catch most of the TSC problems by sanity checks, but there
is a subtle bug which has been in the code for ever. This can cause
time jumps in the range of hours.
This was reported in:
http://lkml.org/lkml/2007/8/23/96
and
http://lkml.org/lkml/2008/3/31/23
I was able to reproduce the problem with a gettimeofday loop test on a
dual core and a quad core machine which both have sychronized
TSCs. The TSCs seems not to be perfectly in sync though, but the
kernel is not able to detect the slight delta in the sync check. Still
there exists an extremly small window where this delta can be observed
with a real big time jump. So far I was only able to reproduce this
with the vsyscall gettimeofday implementation, but in theory this
might be observable with the syscall based version as well.
CPU 0 updates the clock source variables under xtime/vyscall lock and
CPU1, where the TSC is slighty behind CPU0, is reading the time right
after the seqlock was unlocked.
The clocksource reference data was updated with the TSC from CPU0 and
the value which is read from TSC on CPU1 is less than the reference
data. This results in a huge delta value due to the unsigned
subtraction of the TSC value and the reference value. This algorithm
can not be changed due to the support of wrapping clock sources like
pm timer.
The huge delta is converted to nanoseconds and added to xtime, which
is then observable by the caller. The next gettimeofday call on CPU1
will show the correct time again as now the TSC has advanced above the
reference value.
To prevent this TSC specific wreckage we need to compare the TSC value
against the reference value and return the latter when it is larger
than the actual TSC value.
I pondered to mark the TSC unstable when the readout is smaller than
the reference value, but this would render an otherwise good and fast
clocksource unusable without a real good reason.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix obsolete printks in aperture-64. We used not to handle missing
agpgart, but we handle it okay now.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
right now if there's no CPU support for nmi_watchdog=2 we'll just
refuse it silently.
print a useful warning.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
implement nmi_watchdog=2 on this class of CPUs:
cpu family : 15
model : 6
model name : Intel(R) Pentium(R) D CPU 3.00GHz
the watchdog's ->setup() method is safe anyway, so if the CPU
cannot support it we'll bail out safely.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This avoids using wrmsr on MSR_IA32_DEBUGCTLMSR when it's not needed.
No wrmsr ever needs to be done if noone has ever used block stepping.
Without this change, using ptrace on 2.6.25 on an x86 KVM guest
will tickle KVM's missing support for the MSR and crash the guest
kernel. Though host KVM is the buggy one, this makes for a regression
in the guest behavior from 2.6.24->2.6.25 that we can easily avoid.
I also corrected some bad whitespace.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the problem that makedumpfile sometimes fails on x86_64 machine.
This patch adds the symbol "phys_base" to a vmcoreinfo data. The
vmcoreinfo data has the minimum debugging information only for dump
filtering. makedumpfile (dump filtering command) gets it to distinguish
unnecessary pages, and makedumpfile creates a small dumpfile.
On x86_64 kernel which compiled with CONFIG_PHYSICAL_START=0x0 and
CONFIG_RELOCATABLE=y, makedumpfile fails like the following:
# makedumpfile -d31 /proc/vmcore dumpfile
The kernel version is not supported.
The created dumpfile may be incomplete.
_exclude_free_page: Can't get next online node.
makedumpfile Failed.
#
The cause is the lack of the symbol "phys_base" in a vmcoreinfo data.
If the symbol "phys_base" does not exist, makedumpfile considers an
x86_64 kernel as non relocatable. As the result, makedumpfile
misunderstands the physical address where the kernel is loaded, and it
cannot translate a kernel virtual address to physical address correctly.
To fix this problem, this patch adds the symbol "phys_base" to a
vmcoreinfo data.
Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: <stable@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I believe http://bugzilla.kernel.org/show_bug.cgi?id=10318 is a false
positive. There's no way in which networking will be using highmem pages
here, so it won't be taking the KM_USER0 kmap slot, so there's no point in
performing these checks.
Cc: Pawel Staszewski <pstaszewski@artcom.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Really sad. We lose almost all real-life coverage of the debug tests
with this patch. Now it will only report problems for the cases where
people actually end up using a HIGHMEM page, not when they just _might_
use one. - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Took some cycles to re-read the Lguest Journey end-to-end, fix some
rot and tighten some phrases.
Only comments change. No new jokes, but a couple of recycled old jokes.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Linus noticed a second bug and an uncleanliness:
- we'd return on any instruction fetch fault
- we'd use both the value of 16 and the PF_INSTR symbol which are
the same and make no sense
the cleanup nicely unifies this piece of logic.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We need to set up the shared_info pointer once we've mapped the real
shared_info into its fixmap slot. That needs to happen once the general
pagetable setup has been done. Previously, the UP shared_info was set
up one in xen_start_kernel, but that was left pointing to the dummy
shared info. Unfortunately there's no really good place to do a later
setup of the shared_info in UP, so just do it once the pagetable setup
has been done.
[ Stable: needed in 2.6.24.x ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
xen_irq_enable_direct and xen_sysexit were using "andw $0x00ff,
XEN_vcpu_info_pending(vcpu)" to unmask events and test for pending ones
in one instuction.
Unfortunately, the pending flag must be modified with a locked operation
since it can be set by another CPU, and the unlocked form of this
operation was causing the pending flag to get lost, allowing the processor
to return to usermode with pending events and ultimately deadlock.
The simple fix would be to make it a locked operation, but that's rather
costly and unnecessary. The fix here is to split the mask-clearing and
pending-testing into two instructions; the interrupt window between
them is of no concern because either way pending or new events will
be processed.
This should fix lingering bugs in using direct vcpu structure access too.
[ Stable: needed in 2.6.24.x ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The first page of the compound page is determined in follow_huge_addr()
but then PageCompound() only checks if the page is part of a compound page.
PageHead() allows checking if this is indeed the first page of the
compound.
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch fixes the use of GPIO routines which are in the PCI
configuration space of the RDC321x, therefore reading/writing
to this space without spinlock protection can be problematic.
We also now request and free GPIOs and support the MGB100
board, previous code was very AR525W-centric.
Signed-off-by: Volker Weiss <volker@tintuc.de>
Signed-off-by: Florian Fainelli <florian.fainelli@telecomint.eu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/ptrace.c:548: warning: 'ptrace_bts_get_size' defined but not used
arch/x86/kernel/ptrace.c:558: warning: 'ptrace_bts_read_record' defined but not used
arch/x86/kernel/ptrace.c:607: warning: 'ptrace_bts_clear' defined but not used
arch/x86/kernel/ptrace.c:617: warning: 'ptrace_bts_drain' defined but not used
arch/x86/kernel/ptrace.c:720: warning: 'ptrace_bts_config' defined but not used
arch/x86/kernel/ptrace.c:788: warning: 'ptrace_bts_status' defined but not used
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
some early Athlon XP's and Opterons generate bogus faults on prefetch
instructions. The workaround for this regressed over .24 - reinstate it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fix the 3D performance drop reported at:
http://bugzilla.kernel.org/show_bug.cgi?id=10328
fb drivers are using ioremap()/ioremap_nocache(), followed by mtrr_add with
WC attribute. Recent changes in page attribute code made both
ioremap()/ioremap_nocache() mappings as UC (instead of previous UC-). This
breaks the graphics performance, as the effective memory type is UC instead
of expected WC.
The correct way to fix this is to add ioremap_wc() (which uses UC- in the
absence of PAT kernel support and WC with PAT) and change all the
fb drivers to use this new ioremap_wc() API.
We can take this correct and longer route for post 2.6.25. For now,
revert back to the UC- behavior for ioremap/ioremap_nocache.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
we could call find_max_pfn() directly instead of setup_memory() to get
max_pfn needed for mtrr trimming.
otherwise setup_memory() is called two times... that is duplicated...
[ mingo@elte.hu: both Thomas and me simulated a double call to
setup_bootmem_allocator() and can confirm that it is a real bug
which can hang in certain configs. It's not been reported yet but
that is probably due to the relatively scarce nature of
MTRR-trimming systems. ]
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
On Wed, 26 Mar 2008 11:56:22 -0600
Jordan Crouse <jordan.crouse@amd.com> wrote:
> On 26/03/08 14:31 +0100, Stefan Pfetzing wrote:
> > Hello Jordan,
> >
> > I just tried to build your geodwdt driver for the geode watchdog. Therefore
> > I pulled your repository from http://git.infradead.org/geode.git (or more,
> > the git url).
> >
> > I tried to build the geodewdt driver as a module - which didn't work, and
> > it failed with the same problem as earlier mentioned on lkmk [1]. I also
> > checked the fix [2], but that seems to be already in your (or linus) tree -
> > and so I'm unsure what the problem is.
> >
> > [1] http://kerneltrap.org/mailarchive/linux-kernel/2008/2/17/884074
> > [2] http://kerneltrap.org/mailarchive/linux-kernel/2008/2/17/884174
> >
> > Building directly into the kernel seems to work.
> >
> > Maybe you have some idea?
>
> Hmm - that is strange. Exporting the symbols should work. I recommend
> starting over with a clean tree.
>
> CCing Andres - any thoughts?
>
> Jordan
>
Er, yeah. The patch below should fix it. This should probably go into
2.6.25.
Oops, EXPORT_SYMBOL_GPL wasn't being declared due to this header
being missing.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
I have found that using SMI to change the cpu's frequency on my DELL
Latitude L400 clobbers the ECX register in speedstep_set_state, causing
unneccessary retries because the "state" variable has changed silently (GCC
assumes it is still present in ECX).
play safe and avoid gcc caching any register across IO port accesses
that trigger SMIs.
Signed-off by: <Stephan.Diestelhorst@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Convert function comment blocks to kernel-doc notation.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
While backporting 72dc67a696, a gfn_to_page()
call was duplicated instead of moved (due to an unrelated patch not being
present in mainline). This caused a page reference leak, resulting in a
fairly massive memory leak.
Fix by removing the extraneous gfn_to_page() call.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Do not assume that a shadow mapping will always point to the same host
frame number. Fixes crash with madvise(MADV_DONTNEED).
[avi: move after first printk(), add another printk()]
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
The vmx hardware state restore restores the tss selector and base address, but
not its length. Usually, this does not matter since most of the tss contents
is within the default length of 0x67. However, if a process is using ioperm()
to grant itself I/O port permissions, an additional bitmap within the tss,
but outside the default length is consulted. The effect is that the process
will receive a SIGSEGV instead of transparently accessing the port.
Fix by restoring the tss length. Note that i386 had this working already.
Closes bugzilla 10246.
Signed-off-by: Avi Kivity <avi@qumranet.com>
It appears that 64-bit PCI resources cannot possibly ever have worked on
x86-32 even when the RESOURCES_64BIT config option was set, because any
driver that tried to [pci_]ioremap() the resource would have been unable
to do so because the high 32 bits would have been silently dropped on
the floor by the ioremap() routines that only used "unsigned long".
Change them to use "resource_size_t" instead, which properly encodes the
whole 64-bit resource data if RESOURCES_64BIT is enabled.
Acked-by: H. Peter Anvin <hpa@kernel.org>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert
commit f62f1fc9ef
Author: Yinghai Lu <yhlu.kernel@gmail.com>
Date: Fri Mar 7 15:02:50 2008 -0800
x86: reserve dma32 early for gart
The patch has a dependency on bootmem modifications which are not .25
material that late in the -rc cycle. The problem which is addressed by
the patch is limited to machines with 256G and more memory booted with
NUMA disabled. This is not a .25 regression and the audience which is
affected by this problem is very limited, so it's safer to do the
revert than pulling in intrusive bootmem changes right now.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
so use nodedata_phys directly.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
fix the bug reported here:
http://bugzilla.kernel.org/show_bug.cgi?id=10232
use update_memory_range() instead of add_memory_range() directly
to avoid closing the gap.
( the new code only affects and runs on systems where the MTRR
workaround triggers. )
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
we have seen a little problem in rebooting Dell Optiplex 745 with the
0KW626 board. Here is a small patch enabling reboot with this board,
which forces the default reboot path it into the BIOS reboot mode.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The fault_msg text is not explictly nul terminated now in startup
assembly. Do so by converting .ascii to .asciz.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
aperture_64.c takes a piece of memory and makes it into iommu
window... but such window may not be saved by swsusp -- that leads to
oops during hibernation.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
this patch allows hpet=force on nVidia nForce 430 southbridge.
This patch was tested by me on my old Asus A8N-VM CSM (where bios does not
support hpet and does not advertise it via acpi entry). My nForce430 version:
lspci -nn | grep LPC
00:0a.0 ISA bridge [0601]: nVidia Corporation MCP51 LPC Bridge [10de:0260]
(rev a2)
Kernel 2.6.24.3 after patching and using hpet=force reports this:
dmesg | grep -i hpet
Kernel command line: root=/dev/sda8 ro vga=773 video=vesafb:mtrr:4,ywrap
vt.default_utf8=0 hpet=force
Force enabled HPET at base address 0xfed00000
hpet clockevent registered
Time: hpet clocksource has been installed.
grep -i hpet /proc/timer_list
Clock Event Device: hpet
set_next_event: hpet_legacy_next_event
set_mode: hpet_legacy_set_mode
grep Clock /proc/timer_list (before patching)
Clock Event Device: pit
Clock Event Device: lapic
grep Clock /proc/timer_list (after patching)
Clock Event Device: hpet
Clock Event Device: lapic
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
a system with 256 GB of RAM, when NUMA is disabled crashes the
following way:
Your BIOS doesn't leave a aperture memory hole
Please enable the IOMMU option in the BIOS setup
This costs you 64 MB of RAM
Cannot allocate aperture memory hole (ffff8101c0000000,65536K)
Kernel panic - not syncing: Not enough memory for aperture
Pid: 0, comm: swapper Not tainted 2.6.25-rc4-x86-latest.git #33
Call Trace:
[<ffffffff84037c62>] panic+0xb2/0x190
[<ffffffff840381fc>] ? release_console_sem+0x7c/0x250
[<ffffffff847b1628>] ? __alloc_bootmem_nopanic+0x48/0x90
[<ffffffff847b0ac9>] ? free_bootmem+0x29/0x50
[<ffffffff847ac1f7>] gart_iommu_hole_init+0x5e7/0x680
[<ffffffff847b255b>] ? alloc_large_system_hash+0x16b/0x310
[<ffffffff84506a2f>] ? _etext+0x0/0x1
[<ffffffff847a2e8c>] pci_iommu_alloc+0x1c/0x40
[<ffffffff847ac795>] mem_init+0x45/0x1a0
[<ffffffff8479ff35>] start_kernel+0x295/0x380
[<ffffffff8479f1c2>] _sinittext+0x1c2/0x230
the root cause is : memmap PMD is too big,
[ffffe200e0600000-ffffe200e07fffff] PMD ->ffff81383c000000 on node 0
almost near 4G..., and vmemmap_alloc_block will use up the ram under 4G.
solution will be:
1. make memmap allocation get memory above 4G...
2. reserve some dma32 range early before we try to set up memmap for all.
and release that before pci_iommu_alloc, so gart or swiotlb could get some
range under 4g limit for sure.
the patch is using method 2.
because method1 may need more code to handle SPARSEMEM and SPASEMEM_VMEMMAP
will get
Your BIOS doesn't leave a aperture memory hole
Please enable the IOMMU option in the BIOS setup
This costs you 64 MB of RAM
Mapping aperture over 65536 KB of RAM @ 4000000
Memory: 264245736k/268959744k available (8484k kernel code, 4187464k reserved, 4004k data, 724k init)
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We recently got some of the "Desktop Form Factor" Optiplex 745's in. I
noticed that there's an entry for the SFF one's, but the BIOS model number
of the DFF differs from that of the SFF. We have been reliably
experiencing the same (as far as I can tell) reboot bug as the SFF boxes.
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fix visws printk format warnings:
/local/linsrc/linux-2.6.24-git15/arch/x86/mach-visws/traps.c:50: warning: format '%#lx' expects type 'long unsigned int', but argument 2 has type 'u32'
/local/linsrc/linux-2.6.24-git15/arch/x86/mach-visws/traps.c:50: warning: format '%#lx' expects type 'long unsigned int', but argument 3 has type 'u32'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
when numa disabled I got this compile warning:
arch/x86/kernel/setup64.c: In function setup_per_cpu_areas:
arch/x86/kernel/setup64.c:147: warning: the address of
contig_page_data will always evaluate as true
it seems we missed checking if the node is online before we try to refer
NODE_DATA. Fix it.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
memory-less node support:
this patch uses updated dev_to_node, because dev_to_node already makes sure
it returns an online node.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move 00-INDEX entries to power/00-INDEX (and add entry for
pm_qos_interface.txt).
Update references to moved filenames.
Fix some trailing whitespace.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Len Brown <len.brown@intel.com>
quicklists cause a serious memory leak on 32-bit x86,
as documented at:
http://bugzilla.kernel.org/show_bug.cgi?id=9991
the reason is that the quicklist pool is a special-purpose
cache that grows out of proportion. It is not accounted for
anywhere and users have no way to even realize that it's
the quicklists that are causing RAM usage spikes. It was
supposed to be a relatively small pool, but as demonstrated
by KOSAKI Motohiro, they can grow as large as:
Quicklists: 1194304 kB
given how much trouble this code has caused historically,
and given that Andrew objected to its introduction on x86
(years ago), the best option at this point is to remove them.
[ any performance benefits of caching constructed pgds should
be implemented in a more generic way (possibly within the page
allocator), while still allowing constructed pages to be
allocated by other workloads. ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The code to restart syscalls after signals depends on checking for a
negative orig_ax, and for particular negative -ERESTART* values in ax.
These fields are 64 bits and for a 32-bit task they get zero-extended.
The syscall restart behavior is lost, a regression from a native 32-bit
kernel and from 64-bit tasks' behavior.
This patch fixes the problem by doing sign-extension where it matters.
For orig_ax, the only time the value should be -1 but winds up as
0x0ffffffff is via a 32-bit ptrace call. So the patch changes ptrace to
sign-extend the 32-bit orig_eax value when it's stored; it doesn't
change the checks on orig_ax, though it uses the new current_syscall()
inline to better document the subtle importance of the used of
signedness there.
The ax value is stored a lot of ways and it seems hard to get them all
sign-extended at their origins. So for that, we use the
current_syscall_ret() to sign-extend it only for 32-bit tasks at the
time of the -ERESTART* comparisons.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
I figured out another ACPI related regression today.
randconfig testing triggered an early boot-time hang on a laptop of mine
(32-bit x86, config attached) - the screen was scrolling ACPI AML
exceptions [with no serial port and no early debugging available].
v2.6.24 works fine on that laptop with the same .config, so after a few
hours of bisection (had to restart it 3 times - other regressions
interacted), it honed in on this commit:
| 10270d4838 is first bad commit
|
| Author: Linus Torvalds <torvalds@woody.linux-foundation.org>
| Date: Wed Feb 13 09:56:14 2008 -0800
|
| acpi: fix acpi_os_read_pci_configuration() misuse of raw_pci_read()
reverting this commit ontop of -rc5 gave a correctly booting kernel.
But this commit fixes a real bug so the real question is, why did it
break the bootup?
After quite some head-scratching, the following change stood out:
- pci_id->bus = tu8;
+ pci_id->bus = val;
pci_id->bus is defined as u16:
struct acpi_pci_id {
u16 segment;
u16 bus;
...
and 'tu8' changed from u8 to u32. So previously we'd unconditionally
mask the return value of acpi_os_read_pci_configuration()
(raw_pci_read()) to 8 bits, but now we just trust whatever comes back
from the PCI access routines and only crop it to 16 bits.
But if the high 8 bits of that result contains any noise then we'll
write that into ACPI's PCI ID descriptor and confuse the heck out of the
rest of ACPI.
So lets check the PCI-BIOS code on that theory. We have this codepath
for 8-bit accesses (arch/x86/pci/pcbios.c:pci_bios_read()):
switch (len) {
case 1:
__asm__("lcall *(%%esi); cld\n\t"
"jc 1f\n\t"
"xor %%ah, %%ah\n"
"1:"
: "=c" (*value),
"=a" (result)
: "1" (PCIBIOS_READ_CONFIG_BYTE),
"b" (bx),
"D" ((long)reg),
"S" (&pci_indirect));
Aha! The "=a" output constraint puts the full 32 bits of EAX into
*value. But if the BIOS's routines set any of the high bits to nonzero,
we'll return a value with more set in it than intended.
The other, more common PCI access methods (v1 and v2 PCI reads) clear
out the high bits already, for example pci_conf1_read() does:
switch (len) {
case 1:
*value = inb(0xCFC + (reg & 3));
which explicitly converts the return byte up to 32 bits and zero-extends
it.
So zero-extending the result in the PCI-BIOS read routine fixes the
regression on my laptop. ( It might fix some other long-standing issues
we had with PCI-BIOS during the past decade ... ) Both 8-bit and 16-bit
accesses were buggy.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ahmed managed to crash the Host in release_pgd(), which cannot be a Guest
bug, and indeed it wasn't.
The bug was that handing a 0 as the address of the toplevel page table
being manipulated can cause the lookup code in find_pgdir() to return
an uninitialized cache entry (we shadow up to 4 top level page tables
for each Guest).
Commit 37cc8d7f96 introduced this
behaviour in the Guest, uncovering the bug.
The patch which he submitted (which removed the /4 from the index
calculation) simply ensured that these high-indexed entries hit the
early exit path of guest_set_pmd(). But you get lots of segfaults in
guest userspace as the PMDs aren't being updated.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Now the TSC code handles a zero return from calculate_cpu_khz(),
lguest can simply pass through the value it gets from the Host: if
non-zero, all the normal TSC code applies.
Otherwise (or if the Host really doesn't support TSC), the clocksource
code will fall back to the slower but reasonable lguest clock.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This makes 64-bit ptrace calls setting the 64-bit orig_ax field for a
32-bit task sign-extend the low 32 bits up to 64. This matches what a
64-bit debugger expects when tracing a 32-bit task.
This follows on my "x86_64 ia32 syscall restart fix". This didn't
matter until that was fixed.
The debugger ignores or zeros the high half of every register slot it
sets (including the orig_rax pseudo-register) uniformly. It expects
that the setting of the low 32 bits always has the same meaning as a
32-bit debugger setting those same 32 bits with native 32-bit
facilities.
This never arose before because the syscall restart check never
matched any -ERESTART* values due to lack of sign extension. Before
that fix, even 32-bit ptrace setting orig_eax to -1 failed to trigger
the restart check anyway. So this was never noticed as a regression
of 64-bit debuggers vs 32-bit debuggers on the same 64-bit kernel.
Signed-off-by: Roland McGrath <roland@redhat.com>
[ Changed to just do the sign-extension unconditionally on x86-64,
since orig_ax is always just a small integer and doesn't need
the full 64-bit range ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The new x86 setup code (4fd06960f1) broke booting on an old P3/500MHz
with an onboard Voodoo3 of mine. After debugging it, it turned out
to be caused by the fact that the vesa probing now asks for VBE2 data.
Disassembing the video BIOS shows that it overflows the vesa_general_info
structure when VBE2 data is requested because the source addresses for the
information strings which get strcpy'ed to the buffer lie outside the 32K
BIOS code (and hence contain long sequences of 0xff's).
E.G.:
get_vbe_controller_info:
00002A9C 60 pushaw
00002A9D 1E push ds
00002A9E 0E push cs
00002A9F 1F pop ds
00002AA0 2BC9 sub cx,cx
00002AA2 6626813D56424532 cmp dword [es:di],0x32454256 ; "VBE2"
00002AAA 7501 jnz .1
00002AAC 41 inc cx
.1:
00002AAD 51 push cx
00002AAE B91400 mov cx,0x14
00002AB1 BED47F mov si, controller_header
00002AB4 57 push di
00002AB5 F3A4 rep movsb ; copy vbe1.2 header
00002AB7 B9EC00 mov cx,0xec
00002ABA 2AC0 sub al,al
00002ABC F3AA rep stosb ; zero pad remainder
00002ABE 5F pop di
00002ABF E8EB0D call word get_memory
00002AC2 C1E002 shl ax,0x2
00002AC5 26894512 mov [es:di+0x12],ax ; total memory
00002AC9 26C745040003 mov word [es:di+0x4],0x300 ; VBE version
00002ACF 268C4D08 mov [es:di+0x8],cs
00002AD3 268C4D10 mov [es:di+0x10],cs
00002AD7 59 pop cx
00002AD8 E361 jcxz .done ; VBE2 requested?
00002ADA 8D9D0001 lea bx,[di+0x100]
00002ADE 53 push bx
00002ADF 87DF xchg bx,di ; di now points to 2nd half
00002AE1 26C747140001 mov word [es:bx+0x14],0x100 ; sw rev
00002AE7 26897F06 mov [es:bx+0x6],di ; oem string
00002AEB 268C4708 mov [es:bx+0x8],es
00002AEF BE5280 mov si,0x8052 ; oem string
00002AF2 E87A1B call word strcpy
00002AF5 26897F0E mov [es:bx+0xe],di ; video mode list
00002AF9 268C4710 mov [es:bx+0x10],es
00002AFD B91E00 mov cx,0x1e
00002B00 BEE87F mov si,vidmodes
00002B03 F3A5 rep movsw
00002B05 26897F16 mov [es:bx+0x16],di ; oem vendor
00002B09 268C4718 mov [es:bx+0x18],es
00002B0D BE2480 mov si,0x8024 ; oem vendor
00002B10 E85C1B call word strcpy
00002B13 26897F1A mov [es:bx+0x1a],di ; oem product
00002B17 268C471C mov [es:bx+0x1c],es
00002B1B BE3880 mov si,0x8038 ; oem product
00002B1E E84E1B call word strcpy
00002B21 26897F1E mov [es:bx+0x1e],di ; oem product rev
00002B25 268C4720 mov [es:bx+0x20],es
00002B29 BE4580 mov si,0x8045 ; oem product rev
00002B2C E8401B call word strcpy
00002B2F 58 pop ax
00002B30 B90001 mov cx,0x100
00002B33 2BCF sub cx,di
00002B35 03C8 add cx,ax
00002B37 2AC0 sub al,al
00002B39 F3AA rep stosb ; zero pad
.done:
00002B3B 1F pop ds
00002B3C 61 popaw
00002B3D B84F00 mov ax,0x4f
00002B40 C3 ret
(The full BIOS can be found at http://peter.korsgaard.com/vgabios.bin
if interested).
The old setup code didn't ask for VBE2 info, and the new code doesn't
actually do anything with the extra information, so the fix is to simply
not request it. Other BIOS'es might have the same problem.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Jan Beulich noticed that the reboot fixups went missing during
reboot.c unification.
(commit 4d022e35fd)
Geode and a few other rare boards with special reboot quirks are
affected.
Reported-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
convert_fxsr_to_user() in 2.6.24's i387_32.c did this, and
convert_to_fxsr() also does the inverse, so I assume it's an oversight
that it is no longer being done.
[ mingo@elte.hu:
we encode it this way because there's no space for the 'FPU Last
Instruction Opcode' (->fop) field in the legacy user_i387_ia32_struct
that PTRACE_GETFPREGS/PTRACE_SETFPREGS uses.
it's probably pure legacy - i'd be surprised if any user-space relied on
the FPU Last Opcode in any way. But indeed we used to do it previously
so the most conservative thing is to preserve that piece of information.
]
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The Linux kernel currently does not clear the direction flag before
calling a signal handler, whereas the x86/x86-64 ABI requires that.
Linux had this behavior/bug forever, but this becomes a real problem
with gcc version 4.3, which assumes that the direction flag is
correctly cleared at the entry of a function.
This patches changes the setup_frame() functions to clear the
direction before entering the signal handler.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: H. Peter Anvin <hpa@zytor.com>
We don't need to printk a message every time we transition.
Leave the code there, but ifdef'd out, as it's useful when
adding support for new processors.
Reported-by: Petr Titěra <P.Titera@century.cz>
Signed-off-by: Dave Jones <davej@redhat.com>
Add CONFIG_HAVE_KRETPROBES to the arch/<arch>/Kconfig file for relevant
architectures with kprobes support. This facilitates easy handling of
in-kernel modules (like samples/kprobes/kretprobe_example.c) that depend on
kretprobes being present in the kernel.
Thanks to Sam Ravnborg for helping make the patch more lean.
Per Mathieu's suggestion, added CONFIG_KRETPROBES and fixed up dependencies.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
P4 has been coming out as CPU_FAMILY=4 instead of 6: fix MPENTIUM4 typo.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
x86/xen: fix DomU boot problem
x86: not set node to cpu_to_node if the node is not online
x86, i387: fix ptrace leakage using init_fpu()
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm:
x86: disable KVM for Voyager and friends
KVM: VMX: Avoid rearranging switched guest msrs while they are loaded
KVM: MMU: Fix race when instantiating a shadow pte
KVM: Route irq 0 to vcpu 0 exclusively
KVM: Avoid infinite-frequency local apic timer
KVM: make MMU_DEBUG compile again
KVM: move alloc_apic_access_page() outside of non-preemptable region
KVM: SVM: fix Windows XP 64 bit installation crash
KVM: remove the usage of the mmap_sem for the protection of the memory slots.
KVM: emulate access to MSR_IA32_MCG_CTL
KVM: Make the supported cpuid list a host property rather than a vm property
KVM: Fix kvm_arch_vcpu_ioctl_set_sregs so that set_cr0 works properly
KVM: SVM: set NM intercept when enabling CR0.TS in the guest
KVM: SVM: Fix lazy FPU switching
Construct Xen guest e820 map with a hole between 640K-1M.
It's pure luck that Xen kernels have gotten away with it in the past.
The patch below seems like the right thing to do. It certainly boots in
a domU without the DMI problem (without any of the other related patches
such as Alexander's).
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Tested-by: Mark McLoughlin <markmc@redhat.com>
Acked-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
resolve boot problem reported by Mel Gorman:
http://lkml.org/lkml/2008/2/13/404
init_cpu_to_node will use cpu->apic (from MADT or mptable) and
apic->node(from SRAT or AMD config space with k8_bus_64.c) to have
cpu->node mapping, and later identify_cpu will overwrite them
again...(with nearby_node...)
this patch checks if the node is online, otherwise it will not
update cpu_node map. so keep cpu_node map to online node before
identify_cpu..., to prevent possible error.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
This bug got introduced by the recent i387 merge:
commit 4421011120
Author: Roland McGrath <roland@redhat.com>
Date: Wed Jan 30 13:31:50 2008 +0100
x86: x86 i387 user_regset
Current usage of unlazy_fpu() in ptrace specific routines is wrong.
unlazy_fpu() will not init fpu if the task never used math. So the
ptrace calls can expose the parent tasks FPU data in some cases.
Replace it with the init_fpu() which will init the math state, if the
task never used math before.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Most classic Pentiums don't have hardware virtualization extension,
and building kvm with Voyager, Visual Workstation, or NUMAQ
generates spurious failures.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
KVM tries to run as much as possible with the guest msrs loaded instead of
host msrs, since switching msrs is very expensive. It also tries to minimize
the number of msrs switched according to the guest mode; for example,
MSR_LSTAR is needed only by long mode guests. This optimization is done by
setup_msrs().
However, we must not change which msrs are switched while we are running with
guest msr state:
- switch to guest msr state
- call setup_msrs(), removing some msrs from the list
- switch to host msr state, leaving a few guest msrs loaded
An easy way to trigger this is to kexec an x86_64 linux guest. Early during
setup, the guest will switch EFER to not include SCE. KVM will stop saving
MSR_LSTAR, and on the next msr switch it will leave the guest LSTAR loaded.
The next host syscall will end up in a random location in the kernel.
Fix by reloading the host msrs before changing the msr list.
Signed-off-by: Avi Kivity <avi@qumranet.com>
For improved concurrency, the guest walk is performed concurrently with other
vcpus. This means that we need to revalidate the guest ptes once we have
write-protected the guest page tables, at which point they can no longer be
modified.
The current code attempts to avoid this check if the shadow page table is not
new, on the assumption that if it has existed before, the guest could not have
modified the pte without the shadow lock. However the assumption is incorrect,
as the racing vcpu could have modified the pte, then instantiated the shadow
page, before our vcpu regains control:
vcpu0 vcpu1
fault
walk pte
modify pte
fault in same pagetable
instantiate shadow page
lookup shadow page
conclude it is old
instantiate spte based on stale guest pte
We could do something clever with generation counters, but a test run by
Marcelo suggests this is unnecessary and we can just do the revalidation
unconditionally. The pte will be in the processor cache and the check can
be quite fast.
Signed-off-by: Avi Kivity <avi@qumranet.com>
If the local apic initial count is zero, don't start a an hrtimer with infinite
frequency, locking up the host.
Signed-off-by: Avi Kivity <avi@qumranet.com>
the cr3 variable is now inside the vcpu->arch structure.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
alloc_apic_access_page() can sleep, while vmx_vcpu_setup is called
inside a non preemptable region. Move it after put_cpu().
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
While installing Windows XP 64 bit wants to access the DEBUGCTL and the last
branch record (LBR) MSRs. Don't allowing this in KVM causes the installation to
crash. This patch allow the access to these MSRs and fixes the issue.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Markus Rechberger <markus.rechberger@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This patch replaces the mmap_sem lock for the memory slots with a new
kvm private lock, it is needed beacuse untill now there were cases where
kvm accesses user memory while holding the mmap semaphore.
Signed-off-by: Izik Eidus <izike@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Revert:
commit 8be8f54bae
Author: Thomas Gleixner <tglx@linutronix.de>
Date: Sat Feb 23 20:43:21 2008 +0100
x86: CPA: avoid split of alias mappings
because it clearly mishandles the case when __change_page_attr(), called
from __change_page_attr_set_clr(), changes cpa->processed to 1 and
cpa_process_alias(cpa) is executed right after that.
This crashes my x86-64 test box early in the boot process
(ref. http://bugzilla.kernel.org/show_bug.cgi?id=10140#c4).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Injecting an GP when accessing this MSR lets Windows crash when running some
stress test tools in KVM. So this patch emulates access to this MSR.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Markus Rechberger <markus.rechberger@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
One of the use cases for the supported cpuid list is to create a "greatest
common denominator" of cpu capabilities in a server farm. As such, it is
useful to be able to get the list without creating a virtual machine first.
Since the code does not depend on the vm in any way, all that is needed is
to move it to the device ioctl handler. The capability identifier is also
changed so that binaries made against -rc1 will fail gracefully.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Whilst working on getting a VM to initialize in to IA32e mode I found
this issue. set_cr0 relies on comparing the old cr0 to the new one to
work correctly. Move the assignment below so the compare can work.
Signed-off-by: Paul Knowles <paul@transitive.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Explicitly enable the NM intercept in svm_set_cr0 if we enable TS in the guest
copy of CR0 for lazy FPU switching. This fixes guest SMP with Linux under SVM.
Without that patch Linux deadlocks or panics right after trying to boot the
other CPUs.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Markus Rechberger <markus.rechberger@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
If the guest writes to cr0 and leaves the TS flag at 0 while vcpu->fpu_active
is also 0, the TS flag in the guest's cr0 gets lost. This leads to corrupt FPU
state an causes Windows Vista 64bit to crash very soon after boot. This patch
fixes this bug.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Markus Rechberger <markus.rechberger@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Fix 32-on-64 pvops kernel:
we don't want userspace using syscall/sysenter, even if the hypervisor
supports it, so mask it out from CPUID.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
revert the BTS ptrace extension for now.
based on general objections from Roland McGrath:
http://lkml.org/lkml/2008/2/21/323
we'll let the BTS functionality cook some more and re-enable
it in v2.6.26. We'll leave the dead code around to help the
development of this code.
(X86_BTS is not defined at the moment)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
avoid over-eager large page splitup.
When the target area needs to be split or is split already (ioremap)
then the current code enforces the split of large mappings in the alias
regions even if we could avoid it.
Use a separate variable processed in the cpa_data structure to carry
the number of pages which have been processed instead of reusing the
numpages variable. This keeps numpages intact and gives the alias code
a chance to keep large mappings intact.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
delay the removal of this symbol export by one more kernel release,
giving external modules such as VirtualBox a chance to stop using it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Jan Beulich noticed it during code review that if a driver's ioremap()
fails (say due to -ENOMEM) then we might leak the struct vm_area.
Free it properly.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Priit Laes discovered that the sed command processing nm output was
sensitive to locale settings. This was addressed in commit
03994f01e8 by using [:alnum:] in place of
[a-zA-Z0-9].
But that solution too is locale-dependent and may not always match
the identifiers it needs to. The better fix is just to run sed et al
with a fixed locale setting in all builds.
Signed-off-by: Roland McGrath <roland@redhat.com>
CC: Priit Laes <plaes@plaes.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
a recent fix:
commit ce28b9864b
Author: Thomas Gleixner <tglx@linutronix.de>
Date: Wed Feb 20 23:57:30 2008 +0100
x86: fix vsyscall wreckage
removed the broken /kernel/vsyscall64 handler completely.
This triggers the following debug check:
sysctl table check failed: /kernel/vsyscall64 No proc_handler
Restore the sane part of the proc handler.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix a kernel bug (vmware boot problem) reported by Tomasz Grobelny,
which occurs with certain .config variants and gccs.
The x86 TLS cleanup in commit efd1ca52d0
made the sys_set_thread_area and sys_get_thread_area functions ripe for
tail call optimization. If the compiler chooses to use it for them, it
can clobber the user trap frame because these are asmlinkage functions.
Reported-by: Tomasz Grobelny <tomasz@grobelny.oswiecenia.net>
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
> Diffing dmesg between git7 and git8 doesn't sched any light since
> git8 also removed the printouts of the x86 caps as they were being
> initialised and updated. I'm currently adding those printouts back
> in the hope of seeing where and when the caps get broken.
That turned out to be very illuminating:
--- dmesg-2.6.24-git7 2008-02-24 18:01:25.295851000 +0100
+++ dmesg-2.6.24-git8 2008-02-24 18:01:25.530358000 +0100
...
CPU: After generic identify, caps: 00000003 00000000 00000000 00000000 00000000 00000000 00000000 00000000
CPU: After all inits, caps: 00000003 00000000 00000000 00000000 00000000 00000000 00000000 00000000
+CPU: After applying cleared_cpu_caps, caps: 00000013 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Notice how the TSC cap bit goes from Off to On.
(The first two lines are printout loops from -git7 forward-ported
to -git8, the third line is the same printout loop added just after
the xor-with-cleared_cpu_caps[] loop.)
Here's how the breakage occurs:
1. arch/x86/kernel/tsc_32.c:tsc_init() sees !cpu_has_tsc,
so bails and calls setup_clear_cpu_cap(X86_FEATURE_TSC).
2. include/asm-x86/cpufeature.h:setup_clear_cpu_cap(bit) clears
the bit in boot_cpu_data and sets it in cleared_cpu_caps
3. arch/x86/kernel/cpu/common.c:identify_cpu() XORs all caps
in with cleared_cpu_caps
HOWEVER, at this point c->x86_capability correctly has TSC
Off, cleared_cpu_caps has TSC On, so the XOR incorrectly
sets TSC to On in c->x86_capability, with disastrous results.
The real bug is that clearing bits with XOR only works if the
bits are known to be 1 prior to the XOR, and that's not true here.
A simple fix is to convert the XOR to AND-NOT instead. The following
patch does that, and allows my 486 to boot 2.6.25-rc kernels again.
[ mingo@elte.hu: fixed a similar bug in setup_64.c as well. ]
The breakage was introduced via commit 7d851c8d3d.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
For some locales regex range [a-zA-Z] does not work as it is supposed to.
so we have to use [:alnum:] and [:xdigit:] to make it work as intended.
[1] http://en.wikipedia.org/wiki/Estonian_alphabet
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently, c_idle is declared in the stack, and thus, have no static address.
Peter Zijlstra points out this simple solution, in which c_idle.work
is initializated separatedly. Note that the INIT_WORK macro has a static
declaration of a key inside.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Acked-by: Peter Zijlstra <pzijlstr@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently, there is no way for print_stack_trace() to determine whether
a given stack trace entry was deemed reliable or not, simply because
save_stack_trace() does not record this information. (Perhaps needless
to say, this makes the saved stack traces A LOT harder to read, and
probably with no other benefits, since debugging features that use
save_stack_trace() most likely also require frame pointers, etc.)
This patch reverts to the old behaviour of only recording the reliable trace
entries for saved stack traces.
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There doesn't seem to be any reason for swapper_pg_pmd being global.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Inside a KVM virtual machine the MTRRs are usually blank. This confuses Linux
and causes a warning message at boot. This patch removes that warning message
when running Linux as a KVM guest.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
pointed out by pageexec@freemail.hu:
> what happens here is that gcc treats the argument area as owned by the
> callee, not the caller and is allowed to do certain tricks. for ssp it
> will make a copy of the struct passed by value into the local variable
> area and pass *its* address down, and it won't copy it back into the
> original instance stored in the argument area.
>
> so once sys_execve returns, the pt_regs passed by value hasn't at all
> changed and its default content will cause a nice double fault (FWIW,
> this part took me the longest to debug, being down with cold didn't
> help it either ;).
To fix this we pass in pt_regs by pointer.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
based on a report from Arne Georg Gleditsch about user-space apps
misbehaving after toggling /proc/sys/kernel/vsyscall64, a review
of the code revealed that the "NOP patching" done there is
fundamentally unsafe for a number of reasons:
1) the patching code runs without synchronizing other CPUs
2) it inserts NOPs even if there is no clock source which provides vread
3) when the clock source changes to one without vread we run in
exactly the same problem as in #2
4) if nobody toggles the proc entry from 1 to 0 and to 1 again, then
the syscall is not patched out
as a result it is possible to break user-space via this patching.
The only safe thing for now is to remove the patching.
This code was broken since v2.6.21.
Reported-by: Arne Georg Gleditsch <arne.gleditsch@dolphinics.no>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The KERNEL_TEXT_SIZE constant was mis-named, as we not only map the kernel
text but data, bss and init sections as well.
That name led me on the wrong path with the KERNEL_TEXT_SIZE regression,
because i knew how big of _text_ my images have and i knew about the 40 MB
"text" limit so i wrongly thought to be on the safe side of the 40 MB limit
with my 29 MB of text, while the total image size was slightly above 40 MB.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
recently the 64-bit allyesconfig bzImage kernel started spontaneously
rebooting during early bootup.
after a few fun hours spent with early init debugging, it turns out
that we've got this rather annoying limit on the size of the kernel
image:
#define KERNEL_TEXT_SIZE (40*1024*1024)
which limit my vmlinux just happened to pass:
text data bss dec hex filename
29703744 4222751 8646224 42572719 2899baf vmlinux
40 MB is 42572719 bytes, so my vmlinux was just 1.5% above this limit :-/
So it happily crashed right in head_64.S, which - as we all know - is
the most debuggable code in the whole architecture ;-)
So increase the limit to allow an up to 128MB kernel image to be mapped.
(should anyone be that crazy or lazy)
We have a full 4K of pagetable (level2_kernel_pgt) allocated for these
mappings already, so there's no RAM overhead and the limit was rather
pointless and arbitrary.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
notsc is ignored in 32-bit kernels if CONFIG_X86_TSC is on.. which is
bad, fix it.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix mtrr kernel-doc warning:
Warning(linux-2.6.24-git12//arch/x86/kernel/cpu/mtrr/main.c:677): No description found for parameter 'end_pfn'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The proper way to terminate the e820 chain is with %ebx == 0 on the
last legitimate memory block. However, several BIOSes don't do that
and instead return error (CF = 1) when trying to read off the end of
the list. For this error return, %eax doesn't necessarily return the
SMAP signature -- correctly so, since %ah should contain an error code
in this case.
To deal with some particularly broken BIOSes, we clear the entire e820
chain if the SMAP signature is missing in the middle, indicating a
plain insane e820 implementation. However, we need to make the test
for CF = 1 before the SMAP check.
This fixes at least one HP laptop (nc6400) for which none of the
memory-probing methods (e820, e801, 88) functioned fully according to
spec.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
P6_NOPs are definitely not supported on some VIA CPUs, and possibly
(unverified) on AMD K7s. It is also the only thing that prevents a
686 kernel from running on Transmeta TM3x00/5x00 (Crusoe) series.
The performance benefit over generic NOPs is very small, so when
building for generic consumption, avoid using them.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The P6 family of NOPs are only available on family >= 6 or above, so
enforce that in the boot code.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We have been promoting Transmeta TM3x00/TM5x00 chips to i686-class
based on the notion that they contain all the user-space visible
features of an i686-class chip. However, this is not actually true:
they lack the EA-taking long NOPs (0F 1F /0). Since this is a
userspace-visible incompatibility, downgrade these CPUs to the
manufacturer-defined i586 level.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use PF_MEMALLOC to prevent recursive calls in the DBEUG_PAGEALLOC
case. This makes the code simpler and more robust against allocation
failures.
This fixes the following fallback to non-mmconfig:
http://lkml.org/lkml/2008/2/20/551http://bugzilla.kernel.org/show_bug.cgi?id=10083
Also, for DEBUG_PAGEALLOC=n reduce the pool size to one page.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Hi all,
Beginning from commits close to v2.6.25-rc2, running lguest always oopses
the host kernel. Oops is at [1].
Bisection led to the following commit:
commit 37cc8d7f96
x86/early_ioremap: don't assume we're using swapper_pg_dir
At the early stages of boot, before the kernel pagetable has been
fully initialized, a Xen kernel will still be running off the
Xen-provided pagetables rather than swapper_pg_dir[]. Therefore,
readback cr3 to determine the base of the pagetable rather than
assuming swapper_pg_dir[].
static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
{
- pgd_t *pgd = &swapper_pg_dir[pgd_index(addr)];
+ /* Don't assume we're using swapper_pg_dir at this point */
+ pgd_t *base = __va(read_cr3());
+ pgd_t *pgd = &base[pgd_index(addr)];
pud_t *pud = pud_offset(pgd, addr);
pmd_t *pmd = pmd_offset(pud, addr);
Trying to analyze the problem, it seems on the guest side of lguest,
%cr3 has a different value from &swapper_pg-dir (which
is AFAIK fine on a pravirt guest):
Putting some debugging messages in early_ioremap_pmd:
/* Appears 3 times */
[ 0.000000] ***************************
[ 0.000000] __va(%cr3) = c0000000, &swapper_pg_dir = c02cc000
[ 0.000000] ***************************
After 8 hours of debugging and staring on lguest code, I noticed something
strange in paravirt_ops->set_pmd hypercall invocation:
static void lguest_set_pmd(pmd_t *pmdp, pmd_t pmdval)
{
*pmdp = pmdval;
lazy_hcall(LHCALL_SET_PMD, __pa(pmdp)&PAGE_MASK,
(__pa(pmdp)&(PAGE_SIZE-1))/4, 0);
}
The first hcall parameter is global pgdir which looks fine. The second
parameter is the pmd index in the pgdir which is suspectful.
AFAIK, calculating the index of pmd does not need a divisoin over four.
Removing the division made lguest work fine again . Patch is at [2].
I am not sure why the division over four existed in the first place. It
seems bogus, maybe the Xen patch just made the problem appear ?
[2]: The patch:
[PATCH] lguest: fix pgdir pmd index cacluation
Remove an error in index calculation which leads to removing
a not existing shadow page table (leading to a Null dereference).
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Added a declaration to asm-x86/lguest.h and moved the extern arrays there
as well. As an alternative to including asm/lguest.h directly, an
include could be put in linux/lguest.h
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: "rusty@rustcorp.com.au" <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
It's always been broken, but recent fixes actually made it do something,
and now the brokenness shows up as the resulting kernel simply not
working at all.
So it used to be that you could enable this config option, and it just
didn't do anything. Now we'd better stop people from enabling it by
mistake, since it _does_ do something, but does it so badly as to be
unusable.
Code to actually make it work is pending, but incomplete and won't be
merged into 2.6.25 in any case.
Acked-by: Arjan van de Ven <arjan@infradead.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: James Morris <jmorris@namei.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Simple typo fix for regression introduced by the user_regset changes.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make hibernation work with CONFIG_DEBUG_PAGEALLOC set on x86, by
checking if the pages to be copied are marked as present in the
kernel mapping and temporarily marking them as present if that's not
the case. No functional modifications are introduced if
CONFIG_DEBUG_PAGEALLOC is unset.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'agp-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6:
agp: fix missing casts that produced a warning.
agp: add support for 662/671 to agp driver
fix historic ioremap() abuse in AGP
agp/sis: Suspend support for SiS AGP
agp/sis: Clear bit 2 from aperture size byte as well
page_is_ram() has a special case for the 640k-1M bios area, however
due to a thinko the special case checks the e820 table entry and
not the memory the user has asked for. This patch fixes the bug.
[ mingo@elte.hu: this too is better solved in the e820 space, but those
fixes are too intrusive for v2.6.25. ]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch teaches page_is_ram() about the fact that the first
4Kb of memory are special on x86, even though the E820 table
normally doesn't exclude it.
This fixes the WARN_ON() reported by Laurent Riffard who was also
very helpful in diagnosing the issue.
[ mingo@elte.hu: we are working on doing this properly in the e820
space, but for 2.6.25 this is the better fix. ]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Remove redundant irq_desc[NR_IRQS] element initialization in
init_ISA_irqs(). irq_desc[NR_IRQS] is already statically
initialized with the same values in kernel/irq/handle.c .
besides the clean-up value this also saves some space:
text data bss dec hex filename
1389 356 14 1759 6df i8259_32.o.before
1325 356 14 1695 69f i8259_32.o.after
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
I suggest to make the vdso_install step independent as
in following patch.
This solves the issue at ahnd and still gives us the posibility
to install the files should they be needed.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
change back the IO delay to 0x80.
Alan says that 0xed is known to break some older boxes, and given that
the get-rid-of-outb-APIs efforts are well underway we should just let
them be finished.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Though we use PDA for regular task stack but that
is not acceptable for init_task wich is special
one. We still have to allocate init_task's stack
in that manner.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
It's much better to use PAGE_SIZE then magic 4096
(though it's almost synonym in most cases on x86 but
not for *all* cases ;)
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
By including <asm/processor-flags.h> we're allowed to use
X86_CR4_PGE instead of numeric constant.
md5 sums of compiled files are differ due to this inclusion
but .text section remains the same.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This simple patch makes the file error free (according to
checkpatch.pl)
no code changed:
arch/x86/lib/io_64.o:
text data bss dec hex filename
308 0 0 308 134 io_64.o.before
308 0 0 308 134 io_64.o.after
md5:
3c64f9ed83d091678e849b36ca27bee3 io_64.o.before.asm
3c64f9ed83d091678e849b36ca27bee3 io_64.o.after.asm
Signed-off-by: Paolo Ciarrocchi <paolo.ciarrocchi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
initial_code are initially used to hold a function pointer
from __init and later from __cpuinit. This confuses modpost
and changing initial_code to REFDATA silence the warning.
(But now we do not discard the variable anymore).
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
reserve_hotadd() are only used by __init acpi_numa_memory_affinity_init().
Annotate reserve_hotadd() with __init is the trivial fix.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch_register_cpu() is only defined for HOTPLUG_CPU code
so simple fix is to ignore references by annotating the
function __ref.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
srat_detect_node() is only used by __cpuinit init_intel().
So the trivial fix is to annotate srat_detect_node() with __cpuinit.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
nearby_node() were only used by __cpuinit amd_detect_cmp()
So annotating nearby_node() __cpuinit was the trivial fix.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/kernel/nmi_64.c:50: warning: 'unknown_nmi_panic_callback' declared 'static' but never defined
This patch also fixes nmi_32.c
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
New implementation does not use lru for anything so there is no need
to reject pages that are in the LRU. Similar for compound pages (which
were checked because they also use page->lru)
[ tglx@linutronix.de: removed unused variable ]
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Yes, it should.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/kernel/efi_32.c:42:6: warning: symbol 'efi_call_phys_prelog' was not declared. Should it be static?
arch/x86/kernel/efi_32.c:84:6: warning: symbol 'efi_call_phys_epilog' was not declared. Should it be static?
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/kernel/kprobes.c:584:16: warning: symbol 'kretprobe_trampoline_holder' was not declared. Should it be static?
arch/x86/kernel/kprobes.c:676:6: warning: symbol 'trampoline_handler' was not declared. Should it be static?
Make them static and add the __used attribute, approach taken from the
arm kprobes implementation.
kretprobe_trampoline_holder uses inline assemly to define the global
symbol kretprobe_trampoline, but nothing ever calls the holder explicitly.
trampoline handler is only called from inline assembly in the same file,
mark it used and static.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch removes the mca-pentium boot option that was a noop.
besides the source code cleanup factor, this saves some text as well:
arch/x86/kernel/cpu/bugs.o:
text data bss dec hex filename
651 77 4 732 2dc bugs.o.before
631 53 4 688 2b0 bugs.o.after
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Several AGP drivers right now use ioremap_nocache() on kernel ram in order
to turn a page of regular memory uncached.
There are two problems with this:
1) This is a total nightmare for the ioremap() implementation to keep
various mappings of the same page coherent.
2) It's a total nightmare for the AGP code since it adds a ton of
complexity in terms of keeping track of 2 different pointers to
the same thing, in terms of error handling etc etc.
This patch fixes this by making the AGP drivers use the new
set_memory_XX APIs instead.
Note: amd-k7-agp.c is built on Alpha too, and generic.c is built
on ia64 as well, which do not yet have the set_memory_*() APIs,
so for them some we have a few ugly #ifdefs - hopefully they'll
be fixed soon.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Dave Airlie <airlied@linux.ie>
drivers/lguest/x86/switcher_32.S:(.text+0x3815f8):
undefined reference to `LGUEST_PAGES_regs_trapnum'
This problem was caused by asm-offsets.c only having the offsets when
lguest *guest* support was set, not lguest host (host support used to
imply guest support, so now they're separate these bugs come out).
Lguest guest support and host support are separate config options:
they used to be tied together. Sort out which parts of asm-offsets are
needed for Guest and Host.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When the CPA code is called with an virtual address in the range of
the direct mapping or the high alias then we do not need to run
through the alias check for this range.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
NX settings are not required to be consistent across alias mappings.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The early boot code maps KERNEL_TEXT_SIZE (currently 40MB) starting
from __START_KERNEL_map. The kernel itself only needs _text to _end
mapped in the high alias. On relocatible kernels the ASM setup code
adjusts the compile time created high mappings to the relocation. This
creates invalid pmd entries for negative offsets:
0xffffffff80000000 -> pmd entry: ffffffffff2001e3
It points outside of the physical address space and is marked present.
This starts at the virtual address __START_KERNEL_map and goes up to
the point where the first valid physical address (0x0) is mapped.
Zap the mappings before _text and after _end right away in early
boot. This removes also the invalid entries.
Furthermore it simplifies the range check for high aliases.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
c_p_a() did not discover all aliases correctly. (such as when called
on vmalloc()-ed areas or ioremap()-ed areas)
Push the alias checks to the lower, physical level and consistently
discover all aliases that might exist: the low direct mappings and
the high linear kernel-text mappings (on 64-bit).
Thanks to Andi Kleen for pointing out that this was buggy.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
ACPI: DMI: quirk for FSC ESPRIMO Mobile V5505
ACPI: DMI blacklist updates
pnpacpi: __initdata is not an identifier
ACPI: static acpi_chain_head
ACPI: static acpi_find_dsdt_initrd()
ACPI: static acpi_no_initrd_override_setup()
thinkpad_acpi: static
ACPI suspend: Execute _WAK with the right argument
cpuidle: Add Documentation
ACPI, cpuidle: Clarify C-state description in sysfs
ACPI: fix suspend regression due to idle update
The KVM configuration is no longer visible in the latest git tree. It looks
like it is selected by HAVE_SETUP_PER_CPU_AREA. I've moved HAVE_KVM to
under CONFIG_X86.
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
the cpa API is page aligned - warn about any weird alignments.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
extern should not appear in C files. Also, the definitions
do not match the prototype currently, not sure what way you
want to go with this, I've switched the prototype to return
int, but I can see going to the void return as well.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When the GART table is unmapped from the kernel direct mappings
during early bootup, make sure we have no leftover cachelines in it.
Note: the clflush done by set_memory_np() was not enough, because
clflush does not work on unmapped pages.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The EFI-runtime mapping code changed a larger memory area than it
should have, due to a pages/bytes parameter mixup.
noticed by Andi Kleen.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
dump_pagetable() can now become static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Jiri Kosina reported the following deadlock scenario with
show_unhandled_signals enabled:
[ 68.379022] gnome-settings-[2941] trap int3 ip:3d2c840f34
sp:7fff36f5d100 error:0<3>BUG: sleeping function called from invalid
context at kernel/rwsem.c:21
[ 68.379039] in_atomic():1, irqs_disabled():0
[ 68.379044] no locks held by gnome-settings-/2941.
[ 68.379050] Pid: 2941, comm: gnome-settings- Not tainted 2.6.25-rc1 #30
[ 68.379054]
[ 68.379056] Call Trace:
[ 68.379061] <#DB> [<ffffffff81064883>] ? __debug_show_held_locks+0x13/0x30
[ 68.379109] [<ffffffff81036765>] __might_sleep+0xe5/0x110
[ 68.379123] [<ffffffff812f2240>] down_read+0x20/0x70
[ 68.379137] [<ffffffff8109cdca>] print_vma_addr+0x3a/0x110
[ 68.379152] [<ffffffff8100f435>] do_trap+0xf5/0x170
[ 68.379168] [<ffffffff8100f52b>] do_int3+0x7b/0xe0
[ 68.379180] [<ffffffff812f4a6f>] int3+0x9f/0xd0
[ 68.379203] <<EOE>>
[ 68.379229] in libglib-2.0.so.0.1505.0[3d2c800000+dc000]
and tracked it down to:
commit 03252919b7
Author: Andi Kleen <ak@suse.de>
Date: Wed Jan 30 13:33:18 2008 +0100
x86: print which shared library/executable faulted in segfault etc. messages
the problem is that we call down_read() from an atomic context.
Solve this by returning from print_vma_addr() if the preempt count is
elevated. Update preempt_conditional_sti / preempt_conditional_cli to
unconditionally lift the preempt count even on !CONFIG_PREEMPT.
Reported-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add a new sysfs entry under cpuidle states. desc - can be used by driver to
communicate to userspace any specific information about the state.
This helps in identifying the exact hardware C-states behind the ACPI C-state
definition.
Idea is to export this through powertop, which will help to map the C-state
reported by powertop to actual hardware C-state.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
arch/x86/kernel/i8253.c:98:27: warning: symbol 'pit_clockevent' was not declared. Should it be static?
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch enhances EFI runtime code memory mapping as following:
- Move __supported_pte_mask & _PAGE_NX checking before invoking
runtime_code_page_mkexec(). This makes it possible for compiler to
eliminate runtime_code_page_mkexec() on machine without NX support.
- Use set_memory_x/nx in early_mapping_set_exec(). This eliminates the
duplicated implementation.
This patch has been tested on Intel x86_64 platform with EFI64/32
firmware.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Andi Kleen pointed out that the cache attribute logic is reverse in
efi_enter_virtual_mode(). This problem alone is harmless as we do not
(yet) do cache attribute conflict resolution. (This bug was not present
in the original EFI submission - I introduced it while fixing up rejects.)
While reviewing this code I noticed a second, worse problem: the use of
uninitialized md->virt_addr.
Fix both problems.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[ mingo@elte.hu: while gbpages cannot be enabled on mainline currently,
keep the code uptodate and this fix is easy enough. ]
Use correct page sizes and masks for GB pages in try_preserve_large_page()
This prevents a boot hang on a GB capable system with CONFIG_DIRECT_GBPAGES
enabled.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Unpin the Xen-provided pagetable once we've finished with it, so it
doesn't cause stray references which cause later swapper_pg_dir
pagetable updates to fail.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Tested-by: Jody Belka <knew-linux@pimb.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
At the early stages of boot, before the kernel pagetable has been
fully initialized, a Xen kernel will still be running off the
Xen-provided pagetables rather than swapper_pg_dir[]. Therefore,
readback cr3 to determine the base of the pagetable rather than
assuming swapper_pg_dir[].
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Tested-by: Jody Belka <knew-linux@pimb.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When reboot_32.c and reboot_64.c were unified (commit 4d022e35fd...),
the machine_ops code was broken, leading to xen pvops kernels failing
to properly halt/poweroff/reboot etc. This fixes that up.
Signed-off-by: Jody Belka <knew-linux@pimb.org>
Cc: Miguel Boton <mboton@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The makefile magic for installing the 32-bit vdso images on disk had a
little error. A single-line change would fix that bug, but this does a
little more to reduce the error-prone duplication of this bit of
makefile variable magic.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pageattr-test.c contains a noisy debug printk that people reported.
The condition under which it prints (randomly tapping into a mem_map[]
hole and not being able to c_p_a() there) is valid behavior and not
interesting to report.
Remove it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since we may not have a pci_dev for the device we need to access, we can't
use pci_read_config_word. But raw_pci_read is an internal implementation
detail; it's better to use the architected pci_bus_read_config_word
interface. Using PCI_DEVFN instead of a mysterious constant helps
reassure everyone that we really do intend to access device 8.
[ Thanks to Grant Grundler for pointing out to me that this is exactly
what the write immediately above this is doing -- enabling device 8 to
respond to config space cycles.
- Matthew
Grant also says:
"Can you also add a comment which points at the Intel
documentation?
The 'Intel E7320 Memory Controller Hub (MCH) Datasheet' at
http://download.intel.com/design/chipsets/datashts/30300702.pdf
Page 69 documents register F4h (DEVPRES1).
And I just doubled checked that the 0xf4 register value is
restored later in the quirk (obvious when you look at the code
but not from the patch"
so here it is.
- Linus ]
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We want to allow different implementations of pci_raw_ops for standard
and extended config space on x86. Rather than clutter generic code with
knowledge of this, we make pci_raw_ops private to x86 and use it to
implement the new raw interface -- raw_pci_read() and raw_pci_write().
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Thanks to Loic Prylli <loic@myri.com>, who originally proposed
this idea.
Always using legacy configuration mechanism for the legacy config space
and extended mechanism (mmconf) for the extended config space is
a simple and very logical approach. It's supposed to resolve all
known mmconf problems. It still allows per-device quirks (tweaking
dev->cfg_size). It also allows to get rid of mmconf fallback code.
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now, we check only the first 4k page for static required protections.
This does not take overlapping regions into account. So we might end up
setting the wrong permissions/protections for other parts of this large page.
This can be optimized further, but correctness is the important part.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now, that the page pool is in place we can enable DEBUG_PAGEALLOC on
64bit.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Switch the split page code to use the page pool. We do this
unconditionally to avoid different behaviour with and without
DEBUG_PAGEALLOC enabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
DEBUG_PAGEALLOC was not possible on 64-bit due to its early-bootup
hardcoded reliance on PSE pages, and the unrobustness of the runtime
splitup of large pages. The splitup ended in recursive calls to
alloc_pages() when a page for a pte split was requested.
Avoid the recursion with a preallocated page pool, which is used to
split up large mappings and gets refilled in the return path of
kernel_map_pages after the split has been done. The size of the page
pool is adjusted to the available memory.
This part just implements the page pool and the initialization w/o
using it yet.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In some suspend and hibernation files in arch/x86/power there are
comments referring to arch/x86-64 and arch/i386 . Update them to
reflect the current code layout.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move the hibernation-specific code from arch/x86/power/suspend_64.c
to a separate file (hibernate_64.c) and the CPU-handling code to
cpu_64.c (in line with the corresponding 32-bit code).
Simplify arch/x86/power/Makefile .
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Rename cpu.c, suspend.c and swsusp.S in arch/x86/power to cpu_32.c,
hibernate_32.c and hibernate_asm_32.S, respectively, and update the
purpose and copyright information in these files.
Update the Makefile in arch/x86/power to reflect the above changes.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move arch/x86/kernel/suspend_64.c to arch/x86/power .
Move arch/x86/kernel/suspend_asm_64.S to arch/x86/power
as hibernate_asm_64.S .
Update purpose and copyright information in
arch/x86/power/suspend_64.c and
arch/x86/power/hibernate_asm_64.S .
Update the Makefiles in arch/x86, arch/x86/kernel and
arch/x86/power to reflect the above changes.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In arch/x86/boot/printf.c gets rid of unused tail of digits: const char
*digits = "0123456789abcdefghijklmnopqrstuvwxyz"; (we are using 0-9a-f
only)
Uses smaller/faster lowercasing (by ORing with 0x20)
if we know that we work on numbers/digits. Makes
strtoul smaller, and also we are getting rid of
static const char small_digits[] = "0123456789abcdefx";
static const char large_digits[] = "0123456789ABCDEFX";
since this works equally well:
static const char digits[16] = "0123456789ABCDEF";
Size savings:
$ size vmlinux.org vmlinux
text data bss dec hex filename
877320 112252 90112 1079684 107984 vmlinux.org
877048 112252 90112 1079412 107874 vmlinux
It may be also a tiny bit faster because code has less
branches now, but I doubt it is measurable.
[ hugh@veritas.com: uppercase pointers fix ]
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Some important parts of f6df72e71e got
dropped along the way, reintroduce them.
Only affects paravirt guests.
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Specifically the boot time page tables in a CONFIG_X86_PAE=y enabled
kernel are in PAE format.
early_ioremap is updated to use the standard page table accessors.
Clear any mappings beyond max_low_pfn from the boot page tables in
native_pagetable_setup_start because the initial mappings can extend
beyond the range of physical memory and into the vmalloc area.
Derived from patches by Eric Biederman and H. Peter Anvin.
[ jeremy@goop.org: PAE swapper_pg_dir needs to be page-sized fix ]
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Mika Penttilä <mika.penttila@kolumbus.fi>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Other than the defconfigs, remove the entry in compiler-gcc4.h,
Kconfig.debug and feature-removal-schedule.txt.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use a common irq_return entry point for all the iret places, which
need the paravirt INTERRUPT return wrapper.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Adjust the definition of lookup_address to take an unsigned long
level argument. Adjust callers in xen/mmu.c that pass in a
dummy variable.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use xen_khz to denote xen_specific clock speed. Avoid shadowing
cpu_khz.
arch/x86/xen/time.c:220:6: warning: symbol 'cpu_khz' shadows an earlier one
include/asm/tsc.h:17:21: originally declared here
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Each AMD Geode MFGPT timer interrupt output is paired with another
timer; esentially the interrupt goes if either timer fires. This
is okay, but the handlers need to be aware of this. Make sure in
the timer tick handler that our timer really did expire.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We *really* don't want to be reading MFGPTx_SETUP and writing back those
values. What we want to be doing is clearing CMP1 and CMP2 unconditionally;
otherwise, we have races where CMP1 and/or CMP2 fire after we've read
MFGPTx_SETUP. They can also fire between when we've written ~CNTEN to
the register, and when the new register values get copied to the timer's
version of the register. By clearing both fields, we're okay.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There isn't much value to always detecting the MFGPT timers on
Geode platforms; detection is only needed when something wants
to use the timers. Move the detection code so that it gets
called the first time a timer is allocated.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We need to be called from elsewhere, and this gets some #ifdefs out
of the .c file.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Drop F_AVAIL and the 'flags' field, replacing with an 'avail' bit. This
looks more understandable to me.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We had planned to use the 'owner' field for allowing re-allocation of
MFGPTs; however, doing it by module owner name isn't flexible enough. So,
drop this for now. If it turns out that we need timers in modules, we'll
need to come up with a scheme that matches the write-once fields of the
MFGPTx_SETUP register, and drops ponies from the sky.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The GEODE MFGPT code assumed that 32kHz was 32000 Hz while the boards
run on a 32.768 kHz digital watch crystal. In practise, it will not
change the timer's frequency as the skew was only 2.4%, but it
should provide more accurate intervals.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
- uninline timer functions; the compiler knows better than we do
whether or not to inline these.
- mfgpt_start_timer() had an unused 'clock' argument, drop it.
From both Jordan and myself.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild:
Kbuild: Fix deb-pkg target to work with kernel versions ending with -<text-without-digit>
ide: introduce HAVE_IDE
kbuild: silence CHK/UPD messages according to $(quiet)
scsi: fix makefile for aic7(3*x)
kbuild/modpost: Use warn() for announcing section mismatches
Add binoffset to gitignore
kbuild/modpost: improve warnings if symbol is unknown
To allow flexible configuration of IDE introduce HAVE_IDE.
All archs except arm, um and s390 unconditionally select it.
For arm the actual configuration determine if IDE is supported.
This is a step towards introducing drivers/Kconfig for arm.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Russell King - ARM Linux <linux@arm.linux.org.uk>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
The last posted version of this patch gave compile error
on IA64. So, here goes yet another rewrite of the patch.
Convert cpu_idle_wait() to cpuidle_kick_cpus() which is
SMP-only, and gives error on non supported CPU.
Changes from last patch sent by Kevin:
Moved the definition of kick_cpus back to cpuidle.c from cpuidle.h:
* Having it in .h gives #error on archs which includes the header file without
actually having CPU_IDLE configured. To make it work in .h, we need one more
#ifdef around that code which makes it messy.
* Also, the function is only called from one file. So, it can be in declared
statically in .c rather than making it available to everyone who includes
the .h file.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Background: I've implemented 1K/2K page tables for s390. These sub-page
page tables are required to properly support the s390 virtualization
instruction with KVM. The SIE instruction requires that the page tables
have 256 page table entries (pte) followed by 256 page status table entries
(pgste). The pgstes are only required if the process is using the SIE
instruction. The pgstes are updated by the hardware and by the hypervisor
for a number of reasons, one of them is dirty and reference bit tracking.
To avoid wasting memory the standard pte table allocation should return
1K/2K (31/64 bit) and 2K/4K if the process is using SIE.
Problem: Page size on s390 is 4K, page table size is 1K or 2K. That means
the s390 version for pte_alloc_one cannot return a pointer to a struct
page. Trouble is that with the CONFIG_HIGHPTE feature on x86 pte_alloc_one
cannot return a pointer to a pte either, since that would require more than
32 bit for the return value of pte_alloc_one (and the pte * would not be
accessible since its not kmapped).
Solution: The only solution I found to this dilemma is a new typedef: a
pgtable_t. For s390 pgtable_t will be a (pte *) - to be introduced with a
later patch. For everybody else it will be a (struct page *). The
additional problem with the initialization of the ptl lock and the
NR_PAGETABLE accounting is solved with a constructor pgtable_page_ctor and
a destructor pgtable_page_dtor. The page table allocation and free
functions need to call these two whenever a page table page is allocated or
freed. pmd_populate will get a pgtable_t instead of a struct page pointer.
To get the pgtable_t back from a pmd entry that has been installed with
pmd_populate a new function pmd_pgtable is added. It replaces the pmd_page
call in free_pte_range and apply_to_pte_range.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Suppress A.OUT library support if CONFIG_ARCH_SUPPORTS_AOUT is not set.
Not all architectures support the A.OUT binfmt, so the ELF binfmt should not
be permitted to go looking for A.OUT libraries to load in such a case. Not
only that, but under such conditions A.OUT core dumps are not produced either.
To make this work, this patch also does the following:
(1) Makes the existence of the contents of linux/a.out.h contingent on
CONFIG_ARCH_SUPPORTS_AOUT.
(2) Renames dump_thread() to aout_dump_thread() as it's only called by A.OUT
core dumping code.
(3) Moves aout_dump_thread() into asm/a.out-core.h and makes it inline. This
is then included only where needed. This means that this bit of arch
code will be stored in the appropriate A.OUT binfmt module rather than
the core kernel.
(4) Drops A.OUT support for Blackfin (according to Mike Frysinger it's not
needed) and FRV.
This patch depends on the previous patch to move STACK_TOP[_MAX] out of
asm/a.out.h and into asm/processor.h as they're required whether or not A.OUT
format is available.
[jdike@addtoit.com: uml: re-remove accidentally restored code]
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mark arches that support A.OUT format by including the following in their
master Kconfig files:
config ARCH_SUPPORTS_AOUT
def_bool y
This should also be set if the arch provides compatibility A.OUT support for
an older arch, for instance x86_64 for i386 or sparc64 for sparc.
I've guessed at which arches don't, based on comments in the code, however I'm
sure that some of the ones I've marked as 'yes' actually should be 'no'.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix typo in comments.
BTW: I have to fix coding style in arch/ia64/kernel/time.c also, otherwise
checkpatch.pl will be complaining.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide an alternate implementation of the SLUB fast paths for alloc
and free using cmpxchg_local. The cmpxchg_local fast path is selected
for arches that have CONFIG_FAST_CMPXCHG_LOCAL set. An arch should only
set CONFIG_FAST_CMPXCHG_LOCAL if the cmpxchg_local is faster than an
interrupt enable/disable sequence. This is known to be true for both
x86 platforms so set FAST_CMPXCHG_LOCAL for both arches.
Currently another requirement for the fastpath is that the kernel is
compiled without preemption. The restriction will go away with the
introduction of a new per cpu allocator and new per cpu operations.
The advantages of a cmpxchg_local based fast path are:
1. Potentially lower cycle count (30%-60% faster)
2. There is no need to disable and enable interrupts on the fast path.
Currently interrupts have to be disabled and enabled on every
slab operation. This is likely avoiding a significant percentage
of interrupt off / on sequences in the kernel.
3. The disposal of freed slabs can occur with interrupts enabled.
The alternate path is realized using #ifdef's. Several attempts to do the
same with macros and inline functions resulted in a mess (in particular due
to the strange way that local_interrupt_save() handles its argument and due
to the need to define macros/functions that sometimes disable interrupts
and sometimes do something else).
[clameter: Stripped preempt bits and disabled fastpath if preempt is enabled]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
[CPUFREQ] Add missing printk levels to e_powersaver
[CPUFREQ] Fix sparse warning in powernow-k8
[CPUFREQ] Support Model D parts and newer in e_powersaver
[CPUFREQ] Powernow-k8: Update to support the latest Turion processors
[CPUFREQ] fix configuration help message
[CPUFREQ] powernow-k8 print pstate instead of fid/did for family 10h
[CPUFREQ] Eliminate cpufreq_userspace scaling_setspeed deadlock
[CPUFREQ] gx-suspmod.c: use boot_cpu_data instead of current_cpu_data
[CPUFREQ] fix incorrect comment on show_available_freqs() in freq_table.c
[CPUFREQ] drivers/cpufreq: Add missing "space"
[CPUFREQ] arch/x86: Add missing "space"
[CPUFREQ] Remove pointless Kconfig dependancy
Adds i8k driver to the x86_64 Kconfig.
Signed-off-by: Bradley Smith <bradjsmith@btinternet.com>
Cc: Frank Sorenson <frank@tuxrocks.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
struct user.u_ar0 is defined to contain a pointer offset on all
architectures in which it is defined (all architectures which define an
a.out format except SPARC.) However, it has a pointer type in the headers,
which is pointless -- <asm/user.h> is not exported to userspace, and it
just makes the code messy.
Redefine the field as "unsigned long" (which is the same size as a pointer
on all Linux architectures) and change the setting code to user offsetof()
instead of hand-coded arithmetic.
Cc: Linux Arch Mailing List <linux-arch@vger.kernel.org>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: HÃ¥vard Skinnemoen <hskinnemoen@atmel.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes the configuration dependencies in the vmcoreinfo data.
i386's "node_data" is defined in arch/x86/mm/discontig_32.c,
and x86_64's one is defined in arch/x86/mm/numa_64.c.
They depend on CONFIG_NUMA:
arch/x86/mm/Makefile_32:7
obj-$(CONFIG_NUMA) += discontig_32.o
arch/x86/mm/Makefile_64:7
obj-$(CONFIG_NUMA) += numa_64.o
ia64's "pgdat_list" is defined in arch/ia64/mm/discontig.c,
and it depends on CONFIG_DISCONTIGMEM and CONFIG_SPARSEMEM:
arch/ia64/mm/Makefile:9-10
obj-$(CONFIG_DISCONTIGMEM) += discontig.o
obj-$(CONFIG_SPARSEMEM) += discontig.o
ia64's "node_memblk" is defined in arch/ia64/mm/numa.c,
and it depends on CONFIG_NUMA:
arch/ia64/mm/Makefile:8
obj-$(CONFIG_NUMA) += numa.o
Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Acked-by: Simon Horman <horms@verge.net.au>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the BOOTMEM_EXCLUSIVE, introduced in the previous patch, to avoid
conflicts while reserving the memory for the kdump capture kernel
(crashkernel=).
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: <linux-arch@vger.kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchset adds a flags variable to reserve_bootmem() and uses the
BOOTMEM_EXCLUSIVE flag in crashkernel reservation code to detect collisions
between crashkernel area and already used memory.
This patch:
Change the reserve_bootmem() function to accept a new flag BOOTMEM_EXCLUSIVE.
If that flag is set, the function returns with -EBUSY if the memory already
has been reserved in the past. This is to avoid conflicts.
Because that code runs before SMP initialisation, there's no race condition
inside reserve_bootmem_core().
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix powerpc build]
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: <linux-arch@vger.kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a default poll idle state with 0 latency. Provides an option to users
to use poll_idle by using 0 as the latency requirement.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
arch/x86/kernel/cpu/cpufreq/powernow-k8.c:1238:9: warning: symbol '__ptr' shadows an earlier one
arch/x86/kernel/cpu/cpufreq/powernow-k8.c:1238:9: originally declared here
Signed-off-by: Dave Jones <davej@redhat.com>
Patch by VIA that updates e_powersaver.c to work with our model D parts
and newer.
From: Jesse Ahrens <jahrens@centtech.com>
Signed-off-by: Dave Jones <davej@redhat.com>
The latest series of Turion X2 processors have a new XFAM
model. Add support for them to powernow-k8.h.
Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>
In preemptible kernel will report BUG: using smp_processor_id() in
preemptible, so use boot_cpu_data instead of current_cpu_data.
discussion in :
http://lkml.org/lkml/2007/7/25/32
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
CC: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>
lockdep just caught this one:
=================================
[ INFO: inconsistent lock state ]
2.6.24 #38
---------------------------------
inconsistent {in-softirq-W} -> {softirq-on-W} usage.
swapper/1 [HC0[0]:SC0[0]:HE1:SE1] takes:
(pgd_lock){-+..}, at: [<ffffffff8022a9ea>] mm_init+0x1da/0x250
{in-softirq-W} state was registered at:
[<ffffffffffffffff>] 0xffffffffffffffff
irq event stamp: 394559
hardirqs last enabled at (394559): [<ffffffff80267f0a>] get_page_from_freelist+0x30a/0x4c0
hardirqs last disabled at (394558): [<ffffffff80267d25>] get_page_from_freelist+0x125/0x4c0
softirqs last enabled at (393952): [<ffffffff80232f8e>] __do_softirq+0xce/0xe0
softirqs last disabled at (393945): [<ffffffff8020c57c>] call_softirq+0x1c/0x30
other info that might help us debug this:
no locks held by swapper/1.
stack backtrace:
Pid: 1, comm: swapper Not tainted 2.6.24 #38
Call Trace:
[<ffffffff8024e1fb>] print_usage_bug+0x18b/0x190
[<ffffffff8024f55d>] mark_lock+0x53d/0x560
[<ffffffff8024fffa>] __lock_acquire+0x3ca/0xed0
[<ffffffff80250ba8>] lock_acquire+0xa8/0xe0
[<ffffffff8022a9ea>] ? mm_init+0x1da/0x250
[<ffffffff809bcd10>] _spin_lock+0x30/0x70
[<ffffffff8022a9ea>] mm_init+0x1da/0x250
[<ffffffff8022aa99>] mm_alloc+0x39/0x50
[<ffffffff8028b95a>] bprm_mm_init+0x2a/0x1a0
[<ffffffff8028d12b>] do_execve+0x7b/0x220
[<ffffffff80209776>] sys_execve+0x46/0x70
[<ffffffff8020c214>] kernel_execve+0x64/0xd0
[<ffffffff8020901e>] ? _stext+0x1e/0x20
[<ffffffff802090ba>] init_post+0x9a/0xf0
[<ffffffff809bc5f6>] ? trace_hardirqs_on_thunk+0x35/0x3a
[<ffffffff8024f75a>] ? trace_hardirqs_on+0xba/0xd0
[<ffffffff8020c1a8>] ? child_rip+0xa/0x12
[<ffffffff8020bcbc>] ? restore_args+0x0/0x44
[<ffffffff8020c19e>] ? child_rip+0x0/0x12
turns out that pgd_lock has been used on 64-bit x86 in an irq-unsafe
way for almost two years, since commit 8c914cb704.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pavel Emelyanov reported that his networking card did not work
and bisected it down to:
"
The commit
093af8d7f0
x86_32: trim memory by updating e820
broke my e1000 card: on loading driver says that
e1000: probe of 0000:04:03.0 failed with error -5
and the interface doesn't appear.
"
on a 32-bit kernel, base will overflow when try to do PAGE_SHIFT,
and highest_addr will always less 4G.
So use pfn instead of address to avoid the overflow when more than
4g RAM is installed on a 32-bit kernel.
Many thanks to Pavel Emelyanov for reporting and testing it.
Bisected-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Tested-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
delay the CPA self-test so that any impact (corruption) of
user-space pagetables can be triggered. Repeat the test
every 30 seconds.
this would have prevented the bug fixed by 8cb2a7c1e9,
at its source.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The .rodata section really should just be read only; the config option
is there to make breaking up the 2Mb page an option (so people whos machines
give more performance for the 2Mb case can opt to do so).
But when the page gets split anyway, this is no longer an issue, so
clean up the code and remove the ifdefs
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The .rodata section shouldn't just be read-only,
but also non-executable. This is free since we've broken
up the 2MB page already anyway.
also update test_nx to check for this.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This change broke recovery of exceptions in iret:
commit 72fe485854
Author: Glauber de Oliveira Costa <gcosta@redhat.com>
x86: replace privileged instructions with paravirt macros
The ENTRY(native_iret) macro adds alignment padding before the iretq
instruction, so "iret_label" no longer points exactly at the instruction.
It was sloppy to leave the old "iret_label" label behind when replacing
its nearby use. Removing it would have revealed the other use of the
label later in the file, and upon noticing that use, anyone exercising
the minimum of attention to detail expected of anyone touching this
subtle code would realize it needed to change as well.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/cpu/cpufreq/powernow-k8.c:830:7: warning: symbol 'hi' shadows an earlier one
arch/x86/kernel/cpu/cpufreq/powernow-k8.c:824:6: originally declared here
arch/x86/kernel/cpu/cpufreq/powernow-k8.c:830:15: warning: symbol 'lo' shadows an earlier one
arch/x86/kernel/cpu/cpufreq/powernow-k8.c:824:14: originally declared here
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This was being used to ensure the proper alignment of the FXSAVE/FXRSTOR data.
This would create a sparse error in the _correct_ cases, hiding further
warnings. Use BUILD_BUG_ON instead.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In my revamp of the x86 ptrace code for setting register values,
I accidentally omitted a check that was there in the old code.
Allowing %cs to be 0 causes a bad crash in recovery from iret failure.
This patch fixes that regression against 2.6.24, and adds a comment
that should help prevent this subtlety from being overlooked again.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In very rare cases, on certain CPUs, we could end up in the spurious
fault handler and ignore a large pud/pmd mapping. The resulting pte
pointer points into the mapped physical space and dereferencing it
will fault recursively.
Make the code aware of large mappings and do the permission check
on the pmd/pud entry, when a large pud/pmd mapping is detected.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Unify the x86-64 behavior for 32-bit processes that set
bogus %cs/%ss values (the only ones that can fault in iret)
match what the native i386 behavior is. (do not kill the task
via do_exit but generate a SIGSEGV signal)
[ tglx@linutronix.de: build fix ]
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
That patch adds the RTC emulation of the HPET timer to the new RTC_DRV_CMOS.
The old drivers/char/rtc.ko driver had that functionality and it's important
on new systems.
[akpm@linux-foundation.org: unbreak alpha build]
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Robert Picco <Robert.Picco@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Florian Fainelli