Larry Finger reported at http://lkml.org/lkml/2008/9/1/90:
An ancient laptop of mine started throwing errors from b43legacy when
I started using 2.6.27 on it. This has been bisected to commit bfc0f59
"x86: merge tsc calibration".
The unification of the TSC code adopted mostly the 64bit code, which
prefers PMTIMER/HPET over the PIT calibration.
Larrys system has an AMD K6 CPU. Such systems are known to have
PMTIMER incarnations which run at double speed. This results in a
miscalibration of the TSC by factor 0.5. So the resulting calibrated
CPU/TSC speed is half of the real CPU speed, which means that the TSC
based delay loop will run half the time it should run. That might
explain why the b43legacy driver went berserk.
On the other hand we know about systems, where the PIT based
calibration results in random crap due to heavy SMI/SMM
disturbance. On those systems the PMTIMER/HPET based calibration logic
with SMI detection shows better results.
According to Alok also virtualized systems suffer from the PIT
calibration method.
The solution is to use a more wreckage aware aproach than the current
either/or decision.
1) reimplement the retry loop which was dropped from the 32bit code
during the merge. It repeats the calibration and selects the lowest
frequency value as this is probably the closest estimate to the real
frequency
2) Monitor the delta of the TSC values in the delay loop which waits
for the PIT counter to reach zero. If the maximum value is
significantly different from the minimum, then we have a pretty safe
indicator that the loop was disturbed by an SMI.
3) keep the pmtimer/hpet reference as a backup solution for systems
where the SMI disturbance is a permanent point of failure for PIT
based calibration
4) do the loop iteration for both methods, record the lowest value and
decide after all iterations finished.
5) Set a clear preference to PIT based calibration when the result
makes sense.
The implementation does the reference calibration based on
HPET/PMTIMER around the delay, which is necessary for the PIT anyway,
but keeps separate TSC values to ensure the "independency" of the
resulting calibration values.
Tested on various 32bit/64bit machines including Geode 266Mhz, AMD K6
(affected machine with a double speed pmtimer which I grabbed out of
the dump), Pentium class machines and AMD/Intel 64 bit boxen.
Bisected-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Return the correct return value when the CPUID driver partially
completes a request (we should return the number of bytes actually
read or written, instead of the error code.)
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Return the correct return value when the MSR driver partially
completes a request (we should return the number of bytes actually
read or written, instead of the error code.)
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Propagate error (-ENXIO) from smp_call_function_single() in the CPUID
driver. This can happen when a CPU is unplugged while the CPUID
driver is open.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Propagate error (-ENXIO) from smp_call_function_single(). These
errors can happen when a CPU is unplugged while the MSR driver is
open.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
I noticed that my sched_clock() was slow on a number of machine, so I
started looking at cpufreq.
The below seems to fix the problem for me.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: crash on non-TSC-equipped CPUs
Don't enable the TSC notifier if we *either*:
1. don't have a CPU, or
2. have a CPU with constant TSC.
In either of those cases, the notifier is either damaging (1) or useless(2).
From: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
During CPU hot-remove the sysfs directory created by
threshold_create_bank(), defined in
arch/x86/kernel/cpu/mcheck/mce_amd_64.c, has to be removed before
its parent directory, created by mce_create_device(), defined in
arch/x86/kernel/cpu/mcheck/mce_64.c . Moreover, when the CPU in
question is hotplugged again, obviously the latter has to be created
before the former. At present, the right ordering is not enforced,
because all of these operations are carried out by CPU hotplug
notifiers which are not appropriately ordered with respect to each
other. This leads to serious problems on systems with two or more
multicore AMD CPUs, among other things during suspend and hibernation.
Fix the problem by placing threshold bank CPU hotplug callbacks in
mce_cpu_callback(), so that they are invoked at the right places,
if defined. Additionally, use kobject_del() to remove the sysfs
directory associated with the kobject created by
kobject_create_and_add() in threshold_create_bank(), to prevent the
kernel from crashing during CPU hotplug operations on systems with
two or more multicore AMD CPUs.
This patch fixes bug #11337.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Andi Kleen <andi@firstfloor.org>
Tested-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: work around MTRR mask setting, v2
x86: fix section mismatch warning - uv_cpu_init
x86: fix VMI for early params
x86: fix two modpost warnings in mm/init_64.c
x86: fix 1:1 mapping init on 64-bit (memory hotplug case)
x86: work around MTRR mask setting
x86: PAT Update validate_pat_support for intel CPUs
devmem, x86: PAT Change /dev/mem mmap with O_SYNC to use UC_MINUS
x86: PAT proper tracking of set_memory_uc and friends
x86: fix BUG: unable to handle kernel paging request (numaq_tsc_disable)
x86: export pv_lock_ops non-GPL
x86, mmiotrace: silence section mismatch warning - leave_uniprocessor
x86: use WARN() in arch/x86/kernel
x86: use WARN() in arch/x86/mm/ioremap.c
werror: fix pci calgary
x86: fix oprofile + hibernation badness
x86, SGI UV: hardcode the TLB flush interrupt system vector
x86: fix Xorg startup/shutdown slowdown with PAT
x86: fix "kernel won't boot on a Cyrix MediaGXm (Geode)"
x86 iommu: remove unneeded parenthesis
improve the debug printout:
- make it actually display something
- print it only once
would be nice to have a WARN_ONCE() facility, to feed such things to
kerneloops.org.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
WARNING: vmlinux.o(.cpuinit.text+0x3cc4): Section mismatch in reference from the function uv_cpu_init() to the function .init.text:uv_system_init()
The function __cpuinit uv_cpu_init() references
a function __init uv_system_init().
If uv_system_init is only used by uv_cpu_init then
annotate uv_system_init with a matching annotation.
uv_system_init was ment to be called only once, so do it from codepath
(native_smp_prepare_cpus) which is called once, right before activation
of other cpus (smp_init).
Note: old code relied on uv_node_to_blade being initialized to 0,
but it'a not initialized from anywhere.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Acked-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
while fixing a different bug i moved the call to vmi_init before
early params could be parsed.
This broke the vmi specific commandline parameters.
Fix that, by moving vmi initialization after kernel has got a chance to
parse early parameters.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Joshua Hoblitt reported that only 3 GB of his 16 GB of RAM is
usable. Booting with mtrr_show showed us the BIOS-initialized
MTRR settings - which are all wrong.
So the root cause is that the BIOS has not set the mask correctly:
> [ 0.429971] MSR00000200: 00000000d0000000
> [ 0.433305] MSR00000201: 0000000ff0000800
> should be ==> [ 0.433305] MSR00000201: 0000003ff0000800
>
> [ 0.436638] MSR00000202: 00000000e0000000
> [ 0.439971] MSR00000203: 0000000fe0000800
> should be ==> [ 0.439971] MSR00000203: 0000003fe0000800
>
> [ 0.443304] MSR00000204: 0000000000000006
> [ 0.446637] MSR00000205: 0000000c00000800
> should be ==> [ 0.446637] MSR00000205: 0000003c00000800
>
> [ 0.449970] MSR00000206: 0000000400000006
> [ 0.453303] MSR00000207: 0000000fe0000800
> should be ==> [ 0.453303] MSR00000207: 0000003fe0000800
>
> [ 0.456636] MSR00000208: 0000000420000006
> [ 0.459970] MSR00000209: 0000000ff0000800
> should be ==> [ 0.459970] MSR00000209: 0000003ff0000800
So detect this borkage and add the prefix 111.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Pentium III and Core Solo/Duo CPUs have an erratum
" Page with PAT set to WC while associated MTRR is UC may consolidate to UC "
which can result in WC setting in PAT to be ineffective. We will disable
PAT on such CPUs, so that we can continue to use MTRR WC setting.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This section mismatch:
>> Seems to be a section mismatch; init_intel() is __cpuinit while
>> numaq_tsc_disable() is __init. Seems to be introduced in:
>>
>> commit 64898a8bad
>> Author: Yinghai Lu <yhlu.kernel@gmail.com>
>> Date: Sat Jul 19 18:01:16 2008 -0700
>>
>> x86: extend and use x86_quirks to clean up NUMAQ code
>
> Oops, I am wrong about numaq_tsc_disable() being __init. Still, I
> believe that Yinghai might be able to say what's really wrong :-)
Would lead to this crash:
BUG: unable to handle kernel paging request at c08a45f0
IP: [<c08a45f0>] numaq_tsc_disable+0x0/0x40
Fixed by the patch below.
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
None of the spinlock API is exported GPL, so there's no reason for
pv_lock_ops to be.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: drago01 <drago01@gmail.com>
Use WARN() instead of a printk+WARN_ON() pair; this way the message
becomes part of the warning section for better reporting/collection.
This also allowed the folding of some if()'s into the WARN()
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: akpm@linux-foundation.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix an integer comparison always false warning in the PCI Calgary 64 driver.
A u8 is being compared to something that's 512 by default, resulting in the
following warning:
arch/x86/kernel/pci-calgary_64.c:1285: warning: comparison is always false due to limited range of data type
This was introduced by patch b34e90b8f0.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The UV TLB shootdown mechanism needs a system interrupt vector.
Its vector had been hardcoded as 200, but needs to moved to the reserved
system vector range so that it does not collide with some device vector.
This is still temporary until dynamic system IRQ allocation is provided.
But it will be needed when real UV hardware becomes available and runs 2.6.27.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cyrix MediaGXm/Cx5530 Unicorn Revision 1.19.3B has stopped
booting starting at v2.6.22.
The reason is this commit:
> commit f25f64ed5b
> Author: Juergen Beisert <juergen@kreuzholzen.de>
> Date: Sun Jul 22 11:12:38 2007 +0200
>
> x86: Replace NSC/Cyrix specific chipset access macros by inlined functions.
this commit activated a macro which was dormant before due to (buggy)
macro side-effects.
I've looked through various datasheets and found that the GXm and GXLV
Geode processors don't have an incrementor.
Remove the incrementor setup entirely. As the incrementor value
differs according to clock speed and we would hope that the BIOS
configures it correctly, it is probably the right solution.
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This reverts commit 34ae7f35a2, which has
been reported to cause a number of problems. During suspend and resume,
it apparently causes a crash in a CPU hotplug notifier to happen,
although the exact details are sketchy because of the inability to get
good traces during the suspend sequence.
See buzilla entries
http://bugzilla.kernel.org/show_bug.cgi?id=11296http://bugzilla.kernel.org/show_bug.cgi?id=11339
for more examples and details.
[ Mark: "Revert the patch for now. I'm still looking into getting a
reliable reproduction and I do not have a fix at this time." ]
Requested-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Mark Langsdorf <mark.langsdorf@amd.com>
Acked-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@inux-foundation.org>
The parenthesis in __iommu_queue_command() are not needed when assigning
into 'target' variable.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
WARNING: vmlinux.o(.text+0x27032): Section mismatch in reference from the function get_tce_space_from_tar() to the function .init.text:calgary_bus_has_devices()
The function get_tce_space_from_tar() references
the function __init calgary_bus_has_devices().
This is often because get_tce_space_from_tar lacks a __init
annotation or the annotation of calgary_bus_has_devices is wrong.
get_tce_space_from_tar is called only from __init function (calgary_init)
and calls __init function (calgary_bus_has_devices).
So annotate it properly.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Chandru Siddalingappa <chandru@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Take out part of get_local_pda referencing __init function (free_bootmem)
to new (static) function marked as __ref. It's safe to do because free_bootmem
is called before __init sections are dropped.
WARNING: vmlinux.o(.cpuinit.text+0x3cd7): Section mismatch in reference from the function get_local_pda() to the function .init.text:free_bootmem()
The function __cpuinit get_local_pda() references
a function __init free_bootmem().
If free_bootmem is only used by get_local_pda then
annotate free_bootmem with a matching annotation.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/power/cpu_32.c __save_processor_state calls read_cr4()
only a i486 CPU doesn't have the CR4 register. Trying to read it
produces an invalid opcode oops during suspend to disk.
Use the safe rc4 reading op instead. If the value to be written is
zero the write is skipped.
arch/x86/power/hibernate_asm_32.S
done: swapped the use of %eax and %ecx to use jecxz for
the zero test and jump over store to %cr4.
restore_image: s/%ecx/%eax/ to be consistent with done:
In addition to __save_processor_state, acpi_save_state_mem,
efi_call_phys_prelog, and efi_call_phys_epilog had checks added
(acpi restore was in assembly and already had a check for
non-zero). There were other reads and writes of CR4, but MCE and
virtualization shouldn't be executed on a i486 anyway.
Signed-off-by: David Fries <david@fries.net>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
WARNING: vmlinux.o(.text+0x118f7): Section mismatch in reference from the function construct_ioapic_table() to the function .init.text:MP_bus_info()
The function construct_ioapic_table() references
the function __init MP_bus_info().
This is often because construct_ioapic_table lacks a __init
annotation or the annotation of MP_bus_info is wrong.
construct_ioapic_table is called only from construct_default_ISA_mptable which is __init
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
WARNING: arch/x86/kernel/built-in.o(.cpuinit.text+0x1591): Section mismatch in reference from the function init_amd() to the function .init.text:check_enable_amd_mmconf_dmi()
The function __cpuinit init_amd() references
a function __init check_enable_amd_mmconf_dmi().
If check_enable_amd_mmconf_dmi is only used by init_amd then
annotate check_enable_amd_mmconf_dmi with a matching annotation.
check_enable_amd_mmconf_dmi is only called from init_amd which is __cpuinit
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
WARNING: arch/x86/kernel/built-in.o(.cpuinit.text+0x1fe7): Section mismatch in reference from the function MP_processor_info() to the variable .init.data:x86_quirks
The function __cpuinit MP_processor_info() references
a variable __initdata x86_quirks.
If x86_quirks is only used by MP_processor_info then
annotate x86_quirks with a matching annotation.
MP_processor_info uses x86_quirks which is __init and is used only from
smp_read_mpc and construct_default_ISA_mptable which are __init
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
WARNING: vmlinux.o(.text+0x7950): Section mismatch in reference from the function native_calibrate_tsc() to the function .init.text:tsc_read_refs()
The function native_calibrate_tsc() references
the function __init tsc_read_refs().
This is often because native_calibrate_tsc lacks a __init
annotation or the annotation of tsc_read_refs is wrong.
tsc_read_refs is called from native_calibrate_tsc which is not __init
and native_calibrate_tsc cannot be marked __init
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (32 commits)
x86: add MAP_STACK mmap flag
x86: fix section mismatch warning - spp_getpage()
x86: change init_gdt to update the gdt via write_gdt, rather than a direct write.
x86-64: fix overlap of modules and fixmap areas
x86, geode-mfgpt: check IRQ before using MFGPT as clocksource
x86, acpi: cleanup, temp_stack is used only when CONFIG_SMP is set
x86: fix spin_is_contended()
x86, nmi: clean UP NMI watchdog failure message
x86, NMI: fix watchdog failure message
x86: fix /proc/meminfo DirectMap
x86: fix readb() et al compile error with gcc-3.2.3
arch/x86/Kconfig: clean up, experimental adjustement
x86: invalidate caches before going into suspend
x86, perfctr: don't use CCCR_OVF_PMI1 on Pentium 4Ds
x86, AMD IOMMU: initialize dma_ops after sysfs registration
x86m AMD IOMMU: cleanup: replace LOW_U32 macro with generic lower_32_bits
x86, AMD IOMMU: initialize device table properly
x86, AMD IOMMU: use status bit instead of memory write-back for completion wait
x86: silence mmconfig printk
x86, msr: fix NULL pointer deref due to msr_open on nonexistent CPUs
...
By writing directly, a memory access violation can occur whilst
hotplugging a CPU if the entry was previously marked read-only.
Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Cc: Jeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Ftrace depends on some processor state that we destroyed during kexec and
restored by restore_processor_state(). So save_processor_state() and
restore_processor_state() are moved into machine_kexec() and ftrace is
restored after restore_processor_state().
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kexec/Kexec-jump require code size in control page is less than
PAGE_SIZE/2. This patch add link-time checking for this.
ASSERT() of ld link script is used as the link-time checking mechanism.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename KEXEC_CONTROL_CODE_SIZE to KEXEC_CONTROL_PAGE_SIZE, because control
page is used for not only code on some platform. For example in kexec
jump, it is used for data and stack too.
[akpm@linux-foundation.org: unbreak powerpc and arm, finish conversion]
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Plus add a build time check so this doesn't go unnoticed again.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Adds a simple IRQ autodetection to the AMD Geode MFGPT driver, and more
importantly, adds some checks, if IRQs can actually be received on the
chosen line. This fixes cases where MFGPT is selected as clocksource
though not producing any ticks, so the kernel simply starves during
boot.
Signed-off-by: Jens Rottmann <JRottmann@LiPPERTEmbedded.de>
Cc: Andres Salomon <dilinger@debian.org>
Cc: linux-geode@bombadil.infradead.org
Cc: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
fix:
arch/x86/kernel/acpi/sleep.c:24: warning: 'temp_stack' defined but not used
[ Sven Wegener <sven.wegener@stealer.net>: fix build bug ]
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When a CPU core is shut down, all of its caches need to be flushed
to prevent stale data from causing errors if the core is resumed.
Current Linux suspend code performs an assignment after the flush,
which can add dirty data back to the cache. On some AMD platforms,
additional speculative reads have caused crashes on resume because
of this dirty data.
Relocate the cache flush to be the very last thing done before
halting. Tie into an assembly line so the compile will not
reorder it. Add some documentation explaining what is going
on and why we're doing this.
Signed-off-by: Mark Langsdorf <mark.langsdorf@amd.com>
Acked-by: Mark Borden <mark.borden@amd.com>
Acked-by: Michael Hohmuth <michael.hohmuth@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently, setup_p4_watchdog() use CCCR_OVF_PMI1 to enable the counter
overflow interrupts to the second logical core. But this bit doesn't work
on Pentium 4 Ds (model 4, stepping 4) and this patch avoids its use on
these processors. Tested on 4 different machines that have this
specific model with success.
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
Cc: jvillalovos@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If sysfs registration fails all memory used by IOMMU is freed. This
happens after dma_ops initialization and the functions will access the
freed memory then.
Fix this by initializing dma_ops after the sysfs registration.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch adds device table initializations which forbids memory accesses
for devices per default and disables all page faults.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
msr_open tests for someone trying to open a device for a nonexistent CPU.
However, the function always returns 0, not ret like it should, hence
userspace can BUG the kernel trivially. This bug was introduced by the
cdev lock_kernel pushdown patch last May.
The BUG can be reproduced with these commands:
# mknod fubar c 202 8 <-- pick a number less than NR_CPUS that is not
the number of an online CPU
# cat fubar
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
