The real vsyscall .text addresses are not mapped when the alternative()
replacement runs early, so use some black magic to access them using
the direct mapping.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

They already do this in hardware and the Linux algorithm
actually adds errors.

Cc: mingo@elte.hu
Cc: rohit.seth@intel.com
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

o Apic id is in most significant 8 bits of APIC_ID register. Current code
  is trying to write apic id to least significant 8 bits. This patch fixes
  it.

o This fix enables booting uni kdump capture kernel on a cpu with non-zero
  apic id.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove exports that are already exported from the object's source file.
Signed-off-by: NBrian Gerst <bgerst@didntduck.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

These functions are inlines and shouldn't be exported.
Signed-off-by: NBrian Gerst <bgerst@didntduck.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Hopefully the users will take the hint.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

AK: I hacked Muli's original patch a lot and there were a lot
of changes - all bugs are probably to blame on me now.
There were also some changes in the fall back behaviour
for swiotlb - in particular it doesn't try to use GFP_DMA
now anymore. Also all DMA mapping operations use the
same core dma_alloc_coherent code with proper fallbacks now.
And various other changes and cleanups.

Known problems: iommu=force swiotlb=force together breaks
                needs more testing.

This patch cleans up x86_64's DMA mapping dispatching code. Right now
we have three possible IOMMU types: AGP GART, swiotlb and nommu, and
in the future we will also have Xen's x86_64 swiotlb and other HW
IOMMUs for x86_64. In order to support all of them cleanly, this
patch:

- introduces a struct dma_mapping_ops with function pointers for each
  of the DMA mapping operations of gart (AMD HW IOMMU), swiotlb
  (software IOMMU) and nommu (no IOMMU).

- gets rid of:

  if (swiotlb)
      return swiotlb_xxx();

- PCI_DMA_BUS_IS_PHYS is now checked against the dma_ops being set
This makes swiotlb faster by avoiding double copying in some cases.
Signed-Off-By: NMuli Ben-Yehuda <mulix@mulix.org>
Signed-Off-By: NJon D. Mason <jdmason@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This adds a new notifier chain that is called with IDLE_START
when a CPU goes idle and IDLE_END when it goes out of idle.
The context can be idle thread or interrupt context.

Since we cannot rely on MONITOR/MWAIT existing the idle
end check currently has to be done in all interrupt
handlers.

They were originally inspired by the similar s390 implementation.

They have a variety of applications:
- They will be needed for CONFIG_NO_IDLE_HZ
- They can be used for oprofile to fix up the missing time
in idle when performance counters don't tick.
- They can be used for better C state management in ACPI
- They could be used for microstate accounting.

This is just infrastructure so far, no users.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix off by one when checking if the machine has enougn memory to need IOMMU
This caused the IOMMUs to be needlessly enabled for mem=4G

Based on a patch from Jon Mason

Signed-off-by: jdmason@us.ibm.com
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Whenever we see that a CPU is capable of C3 (during ACPI cstate init), we
disable local APIC timer and switch to using a broadcast from external timer
interrupt (IRQ 0).

Patch below adds the code for x86_64.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove the finer control of local APIC timer. We cannot provide a sub-jiffy
control like this when we use broadcast from external timer in place of
local APIC. Instead of removing this only on systems that may end up using
broadcast from external timer (due to C3), I am going the
"I'm feeling lucky" way to remove this fully. Basically, I am not sure about
usefulness of this code today. Few other architectures also don't seem to
support this today.

If you are using profiling and fine grained control and don't like this going
away in normal case, yell at me right now.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I would like to throw out a suggestion for a possible change in the way that
the debug register traps are handled in do_debug() when the trap occurs
in kernel-mode.

In the x86_64 version of do_debug(), the code will skip around sending
a SIGTRAP to the current task if the trap occurred while in kernel mode.

On the i386-side of things, if the access happens to occur in kernel mode
(say during a read(2) of user's buffer that matches the address of a
debug register trap), then the do_debug() routine for i386 will go ahead
and call send_sigtrap() and send the SIGTRAP signal.  The send_sigtrap()
code will also set the info.si_addr to NULL in this case (even though I
don't understand why, since the SIGTRAP siginfo processing doesn't use
the si_addr field...).

So I would like to suggest that the x86_64 do_debug() routine also
follow this type of behavior and have it go ahead and send the
SIGTRAP signal to the current task, even if the debug register trap
happens to have occurred in kernel mode.  I have taken a stab at
a patch for this change below.  (It includes the i386-ish change
for setting si_addr to NULL when the trap occurred in kernel mode.)

It seems like a useful feature to be able to 'watch' a user location that
might also be modified in the kernel via a system service call, and have the
debugger report that information back to the user, rather than to just
silently ignore the trap.

Additionally, I realize that users that pull in a kernel debugger such as
KGDB into their kernel might want to remove this change below when they add
in KGDB support.  However, they could alternatively look at the current
task's thread.debugreg[] values to see if the trap occurred due to KGDB
or instead because of a user-space debugger trap, and still honor the
user SIGTRAP processing (instead of the KGDB breakpoint processing)
if the trap matches up with the thread.debugreg[] registers.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

By setting a flag during a 32bit system call only
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch is on the same lines as Zachary Amsden's i386 GDT page alignemnt
patch in -mm, but for x86_64.

Patch to align and pad x86_64 GDT on page boundries.

[AK: some minor cleanups and fixed incorrect TLS initialization
in CPU init.]
Signed-off-by: NNippun Goel <nippung@calsoftinc.com>
Signed-off-by: NRavikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: NShai Fultheim <shai@scalex86.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This might help on distributions that use a 32bit biarch compiler.

First pass -m64 by default.

Secondly add some more .code32s because at least the Ubuntu biarch
32bit as called by gcc doesn't seem to handle -m64 -m32 as generated
by the Makefile without such assistance.

And finally make sure the linker script can be preprocessed
with a 32bit cpp.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Some people need it now on 64bit so reuse the i386 code for
x86-64. This will be also useful for future bug workarounds.

It is a bit simplified there because there is no need
to do it very early on x86-64. This means it doesn't need
early ioremap et.al. We run it as a core initcall right now.

I hope it's not needed for early setup.

I added a general CONFIG_DMI symbol in case IA64 or someone
else wants to reuse the code later too.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The introduction of call_softirq switching to the interrupt stack several
releases earlier resulted in a problem with the code in show_trace, which
assumes that it can pick the previous stack pointer from the end of the
interrupt stack.

Cc: Andi Kleen <ak@muc.de>
Cc: Arjan van de Ven <arjanv@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

So why are we calling smp_send_stop from machine_halt?

We don't.

Looking more closely at the bug report the problem here
is that halt -p is called which triggers not a halt but
an attempt to power off.

machine_power_off calls machine_shutdown which calls smp_send_stop.

If pm_power_off is set we should never make it out machine_power_off
to the call of do_exit.  So pm_power_off must not be set in this case.
When pm_power_off is not set we expect machine_power_off to devolve
into machine_halt.

So how do we fix this?

Playing too much with smp_send_stop is dangerous because it
must also be safe to be called from panic.

It looks like the obviously correct fix is to only call
machine_shutdown when pm_power_off is defined.  Doing
that will make Andi's assumption about not scheduling
true and generally simplify what must be supported.

This turns machine_power_off into a noop like machine_halt
when pm_power_off is not defined.

If the expected behavior is that sys_reboot(LINUX_REBOOT_CMD_POWER_OFF)
becomes sys_reboot(LINUX_REBOOT_CMD_HALT) if pm_power_off is NULL
this is not quite a comprehensive fix as we pass a different parameter
to the reboot notifier and we set system_state to a different value
before calling device_shutdown().

Unfortunately any fix more comprehensive I can think of is not
obviously correct.  The core problem is that there is no architecture
independent way to detect if machine_power will become a noop, without
calling it.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I noticed that some lowlevel send_IPI_mask helpers had a hotplug/preempt
race whereupon the cpu_online_map was read before disabling preemption;

...
cpumask_t mask = cpu_online_map;
int cpu = get_cpu();
cpu_clear(cpu, mask);
...

But then i realised that there is no need for these lowlevel functions to
be going through all this trouble when all the callers are already made
hotplug/preempt safe.
Signed-off-by: NZwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There is one CPU here whose MCE bank count is 6. This patch increases
x86_64's MCE bank count.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The following is probably a good idea given that the atomic_set() isn't
a barrier here either.
Signed-off-by: NBenjamin LaHaise <benjamin.c.lahaise@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This
- switches the INT3 handler to run on an IST stack (to cope with
  breakpoints set by a kernel debugger on places where the kernel's
  %gs base hasn't been set up, yet); the IST stack used is shared with
  the INT1 handler's
[AK: this also allows setting a kprobe on the interrupt/exception entry
points]
- allows nesting of INT1/INT3 handlers so that one can, with a kernel
  debugger, debug (at least) the user-mode portions of the INT1/INT3
  handling; the nesting isn't actively enabled here since a kernel-
  debugger-free kernel doesn't need it
Signed-Off-By: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Previously apic was foced with apic=logopt was specified.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It might be still needed for non APIC related issues.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Print bits for RDTSCP, SVM, CR8-LEGACY.

Also now print power flags on i386 like x86-64 always did.
This will add a new line in the 386 cpuinfo, but that shouldn't
be an issue - did that in the past too and I haven't heard
of any breakage.

I shrunk some of the fields in the i386 cpuinfo_x86 to chars
to make up for the new int "x86_power" field. Overall it's
smaller than before.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Define it for i386 too.

This is a synthetic flag that signifies that the CPU's TSC runs
at a constant P state invariant frequency.

Fix up the logic on x86-64/i386 to set it on all known CPUs.
Use the AMD defined bit to set it on future AMD CPUs.

Cc: venkatesh.pallipadi@intel.com
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Was only used by the floppy driver to work around some ancient
hardware bug that should never occur on any 64bit system.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Most users don't need it so no need to waste memory.
This means an user has to specify the appropiate number of
hotplug CPUs on the command line with additional_cpus=...
or fix their BIOS to follow the convention in
Documentation/x86-64/cpu-hotplug-spec
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

head.S already clears EFLAGS completely. Following an i386 patch from
Zachary Amsden.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make sure no iret can fault without attached recovery code.
Cannot happen in the normal case, but might be useful
with kernel debuggers
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Since a double fault always implies that kernel data structures are
corrupt, this fault should neither be handed to user mode handling,
nor should the handler allow resuming the faulting code stream (since
architecturally this isn't a fault, but an abort).

Note that this slightly depends on the previously submitted patch
adjusting the prototype of notify_die() (a compiler warning will result
without that other patch).

AK: Removed obsolete CONFIG_CHECKING code, added comments
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This adjusts things so that handlers of the die() notifier will have
sufficient information about the trap currently being handled. It also
adjusts the notify_die() prototype to (again) match that of i386.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Other than apparently commonly assumed, the bound instruction does not
require the corresponding IDT entry to have DPL 3.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

As a follow-up to the introduction of CONFIG_UNWIND_INFO, this
separates the generation of frame unwind information for x86-64 from
that of full debug information.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Based on the documentation recently posted by Richard Brunner.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch: Use <linux/capability.h> where capable() is used.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There is a window where a probe gets removed right after the probe is hit
on some different cpu.  In this case probe handlers can't find a matching
probe instance related to break address.  In this case we need to read the
original instruction at break address to see if that is not a break/int3
instruction and recover safely.

Previous code had a bug where we were not checking for the above race in
case of reentrant probes and the below patch fixes this race.

Tested on IA64, Powerpc, x86_64.
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The following patch (against 2.6.15-rc5-mm3) fixes a kprobes build break
due to changes introduced in the kprobe locking in 2.6.15-rc5-mm3.  In
addition, the patch reverts back the open-coding of kprobe_mutex.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>