Since v->counter is both read and written, it should be an output as well
as an input for the asm. The current code only gets away with this because
counter is volatile. Also, according to Documents/atomic_ops.txt,
atomic_add_return should provide a memory barrier, in particular a compiler
barrier, so the asm should be marked as clobbering memory.
Test case:
#include <stdio.h>
typedef struct { int counter; } atomic_t; /* NB: no "volatile" */
#define ATOMIC_INIT(i) { (i) }
#define atomic_read(v) ((v)->counter)
static __inline__ int atomic_add_return(int i, atomic_t *v)
{
int __i = i;
__asm__ __volatile__(
"lock; xaddl %0, %1;"
:"=r"(i)
:"m"(v->counter), "0"(i));
/* __asm__ __volatile__(
"lock; xaddl %0, %1"
:"+r" (i), "+m" (v->counter)
: : "memory"); */
return i + __i;
}
int main (void) {
atomic_t a = ATOMIC_INIT(0);
int x;
x = atomic_add_return (1, &a);
if ((x!=1) || (atomic_read(&a)!=1))
printf("fail: %i, %i\n", x, atomic_read(&a));
}
Signed-off-by: Duncan Sands <baldrick@free.fr>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Nothing in include/asm-x86_64/cpufeature.h is part of the
userspace<->kernel interface.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Add debugging printks to the unwinder to allow easier debugging
when something goes wrong with it.
This can be controlled with the new unwinder_debug=N option
Most output is given by N=1
AK: Added documentation of unwinder_debug=
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
- Remove "Disabling IOMMU" message because it confuses people
- Clarify that the GART IOMMU is refered to in other message
Signed-off-by: Andi Kleen <ak@suse.de>
Idle callbacks has some races when enter_idle() sets isidle and subsequent
interrupts that can happen on that CPU, before CPU goes to idle. Due to this,
an IDLE_END can get called before IDLE_START. To avoid these races, disable
interrupts before enter_idle and make sure that all idle routines do not
enable interrupts before entering idle.
Note that poll_idle() still has a this race as it has to enable interrupts
before going to idle. But, all other idle routines have the race fixed.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
This was added as a workaround for the fallback unwinder not supporting
unaligned stack pointers properly. But now it was fixed to do that,
so it's not needed anymore
Cc: mingo@elte.hu
Signed-off-by: Andi Kleen <ak@suse.de>
Tighten the requirements on both input to and output from the Dwarf2
unwinder.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
We're already well protected against module unloads because module
unload uses stop_machine(). The only exception is NMIs, but other
users already risk lockless accesses here.
This avoids some hackery in lockdep and also a potential deadlock
This matches what i386 does.
Signed-off-by: Andi Kleen <ak@suse.de>
This avoids trouble with the page fault handler if the fault
happens inside an interrupt context.
Suggested by Linus
Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
On the Core2 cpus, the rdtsc instruction is not serializing (as defined
in the architecture reference since rdtsc exists) and due to the deep
speculation of these cores, it's possible that you can observe time go
backwards between cores due to this speculation. Since the kernel
already deals with this with the SYNC_RDTSC flag, the solution is
simple, only assume that the instruction is serializing on family 15...
The price one pays for this is a slightly slower gettimeofday (by a
dozen or two cycles), but that increase is quite small to pay for a
really-going-forward tsc counter.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
There is no guarantee that two RDTSCs in a row are monotonic,
so don't assume it on single core AMD systems.
This will make gettimeofday slower again
Signed-off-by: Andi Kleen <ak@suse.de>
-mregparm=3 has been enabled by default for some time on i386, and AFAIK
there aren't any problems with it left.
This patch removes the REGPARM config option and sets -mregparm=3
unconditionally.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Sometimes the soft watchdog fires after we're done oopsing.
See http://projects.info-pull.com/mokb/MOKB-25-11-2006.html for an example.
AK: changed to touch_nmi_watchdog()
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Make mce_remove_device() clean up the kobject in per_cpu(device_mce, cpu)
after it has been unregistered.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andi Kleen <ak@suse.de>
interrupt array is referred for idt vectors instead of NR_IRQS, so change size
to NR_VECTORS - FIRST_EXTERNAL_VECTOR. Also change to static.
Signed-off-by: Yinghai Lu <yinghai@amd.com>
Signed-off-by: Andi Kleen <ak@suse.de>
idt_table is in the .bss section, so clear_bss need to called at first
Signed-off-by: Yinghai Lu <yinghai.lu@amd.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Add sysctl for kstack_depth_to_print. This lets users change
the amount of raw stack data printed in dump_stack() without
having to reboot.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>
We do the exact same printk about a dozen lines above
with no intermediate printk's.
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>
When using memmap kernel parameter in EFI boot we should also add to memory map
memory regions of runtime services to enable their mapping later.
AK: merged and cleaned up the patch
Signed-off-by: Artiom Myaskouvskey <artiom.myaskouvskey@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Read/Write APIC_LVTPC and APIC_LVTTHMR only,
if get_maxlvt() returns certain values.
This is done like everywhere else in i386/kernel/apic.c,
so I guess its correct.
Suspends/Resumes to disk fine and eleminates an smp_error_interrupt()
here on a K8.
AK: ported to x86-64 too
Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Signed-off-by: Andi Kleen <ak@suse.de>
There are two consumers of apic=: the apic debug level and the low
level generic architecture code. early_param would warn when the
low level code rejected "debug". Avoid this.
Signed-off-by: Andi Kleen <ak@suse.de>
Here is a small patch for i386 which adds a cpufeature flag and
detection code for Intel's Branch Trace Store (BTS) feature. This
feature can be found on Intel P4 and Core 2 processors among others.
It can also be used by perfmon.
changelog:
- add CPU_FEATURE_BTS
- add Branch Trace Store detection
signed-off-by: stephane eranian <eranian@hpl.hp.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Here is a small patch for x86-64 which adds a cpufeature flag and
detection code for Intel's Branch Trace Store (BTS) feature. This
feature can be found on Intel P4 and Core 2 processors among others.
It can also be used by perfmon.
changelog:
- add CPU_FEATURE_BTS
- add Branch Trace Store detection
signed-off-by: stephane eranian <eranian@hpl.hp.com>
Signed-off-by: Andi Kleen <ak@suse.de>
irq_vector[] can now become static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
The Coverity checker noted that bad things might happen if
find_isa_irq_apic() returned -1.
[akpm@osdl.org: add debugging checks]
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Acked-by: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Function efi_get_time called not only during init kernel phase but also
during suspend (from get_cmos_time).
When it is called from get_cmos_time the corresponding runtime service
should be called in virtual and not in physical mode.
Signed-off-by: Artiom Myaskouvskey <artiom.myaskouvskey@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: "Narayanan, Chandramouli" <chandramouli.narayanan@intel.com>
Cc: "Jiossy, Rami" <rami.jiossy@intel.com>
Cc: "Satt, Shai" <shai.satt@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Move the irqbalance quirks for E7320/E7520/E7525(Errata 23 in
http://download.intel.com/design/chipsets/specupdt/30304203.pdf) to early
quirks.
And add a PCI quirk for these platforms to check(which happens very late
during the boot) if the APIC routing is indeed set to default flat mode.
This fixes the breakage(in x86_64) of this quirk due to cpu hotplug which
selects physical mode instead of the logical flat(as needed for this errata
workaround).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Change the 'no_control' field in the cpu struct to a more positive
and better term 'hotpluggable'. And change(/cleanup) the logic accordingly.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Add 'enable_cpu_hotplug' flag and when cleared, the hotplug control file
("online") will not be added under /sys/devices/system/cpu/cpuX/
Next patch doing PCI quirks will use this.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Mechanism of selecting physical mode in genapic when cpu hotplug is enabled on
x86_64, broke the quirk(quirk_intel_irqbalance()) introduced for working
around the transposing interrupt message errata in E7520/E7320/E7525 (revision
ID 0x9 and below. errata #23 in
http://download.intel.com/design/chipsets/specupdt/30304203.pdf).
This errata requires the mode to be in logical flat, so that interrupts can be
directed to more than one cpu(and thus use hardware IRQ balancing enabled by
BIOS on these platforms).
Following four patches fixes this by moving the quirk to early quirk and
forcing the x86_64 genapic selection to logical flat on these platforms.
Thanks to Shaohua for pointing out the breakage.
This patch:
Add write_pci_config_byte() to direct PCI access routines
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
o Convert more absolute symbols to section relative to keep the theme in
vmlinux.lds.S file and to avoid problem if kernel is relocated.
o Also put a message so that in future people can be aware of it and
avoid introducing absolute symbols.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
o On some platforms like avr32, section init comes before .text and
not necessarily a symbol's relative position w.r.t _text is positive.
In such cases assembler detects the overflow and emits warning. This
patch fixes it.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Make the needlessly global alloc_gdt() static.
(against) pda-percpu-init
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@muc.de>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Until not so long ago, there were system log messages pointing to
inconsistent MTRR setup of the video frame buffer caused by the way vesafb
and X worked. While vesafb was fixed meanwhile, I believe fixing it there
only hides a shortcoming in the MTRR code itself, in that that code is not
symmetric with respect to the ordering of attempts to set up two (or more)
regions where one contains the other. In the current shape, it permits
only setting up sub-regions of pre-exisiting ones. The patch below makes
this symmetric.
While working on that I noticed a few more inconsistencies in that code,
namely
- use of 'unsigned int' for sizes in many, but not all places (the patch
is converting this to use 'unsigned long' everywhere, which specifically
might be necessary for x86-64 once a processor supporting more than 44
physical address bits would become available)
- the code to correct inconsistent settings during secondary processor
startup tried (if necessary) to correct, among other things, the value
in IA32_MTRR_DEF_TYPE, however the newly computed value would never get
used (i.e. stored in the respective MSR)
- the generic range validation code checked that the end of the
to-be-added range would be above 1MB; the value checked should have been
the start of the range
- when contained regions are detected, previously this was allowed only
when the old region was uncacheable; this can be symmetric (i.e. the new
region can also be uncacheable) and even further as per Intel's
documentation write-trough and write-back for either region is also
compatible with the respective opposite in the other
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Make pmd_bad() symmetrical to pgd_bad() and pud_bad(). At once,
simplify them all.
TBD: tighten down the checks again as suggested by Hugh D.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Just like on x86-64, don't touch foreign CPUs' memory if the watchdog
isn't enabled at all.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
While not strictly required with the current code (as the upper half of
page table entries generated by __set_fixmap() cannot be non-zero due
to the second parameter of this function being 'unsigned long'), the
use of set_pte() in __set_fixmap() in the context of clear_fixmap() is
still improper with CONFIG_X86_PAE (see the respective comment in
include/asm-i386/pgtable-3level.h) and would turn into a bug if that
second parameter ever gets changed to a 64-bit type.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
