sys_migrate_pages implementation using swap based page migration

This is the original API proposed by Ray Bryant in his posts during the first
half of 2005 on linux-mm@kvack.org and linux-kernel@vger.kernel.org.

The intent of sys_migrate is to migrate memory of a process.  A process may
have migrated to another node.  Memory was allocated optimally for the prior
context.  sys_migrate_pages allows to shift the memory to the new node.

sys_migrate_pages is also useful if the processes available memory nodes have
changed through cpuset operations to manually move the processes memory.  Paul
Jackson is working on an automated mechanism that will allow an automatic
migration if the cpuset of a process is changed.  However, a user may decide
to manually control the migration.

This implementation is put into the policy layer since it uses concepts and
functions that are also needed for mbind and friends.  The patch also provides
a do_migrate_pages function that may be useful for cpusets to automatically
move memory.  sys_migrate_pages does not modify policies in contrast to Ray's
implementation.

The current code here is based on the swap based page migration capability and
thus is not able to preserve the physical layout relative to it containing
nodeset (which may be a cpuset).  When direct page migration becomes available
then the implementation needs to be changed to do a isomorphic move of pages
between different nodesets.  The current implementation simply evicts all
pages in source nodeset that are not in the target nodeset.

Patch supports ia64, i386 and x86_64.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This was harmless, but for the case of a device that had no irq
pre-defined we would incorrectly suggest that "usepirqmask" might make a
difference.  It never would, and the message was just confusing people.

Reported in the dmesg of Etienne Lorrain.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NBen Collins <bcollins@ubuntu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

o Currently, during kexec reboot, IOAPIC is re-programmed back to virtual
  wire mode if there was an i8259 connected to it. This enables getting
  timer interrupts in second kernel in legacy mode.

o After putting into virtual wire mode, IOAPIC delivers the i8259 interrupts
  to CPU0. This works well for kexec but not for kdump as we might crash
  on a different CPU and second kernel will not see timer interrupts.

o This patch modifies the redirection table entry to deliver the timer
  interrupts to the cpu we are rebooting (instead of hardcoding to zero).
  This ensures that second kernel receives timer interrupts even on a
  non-boot cpu.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When we re-calibrate the frequency, it is likely that an interrupt (as for
example the main system clock) will be triggered by the system.  Therefore
the calibration may not be accurate.  This will also provide a fix to bug
#5266.

Many thanks to Larry Finger for helping resolving this issue.
Signed-off-by: NBruno Ducrot <ducrot@poupinou.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- Fix screen blanking on BIOSes that return APM_NOT_ENGAGED when APM enabled
  screen blanking is not turned on.

  The original code only tried to set the state on device 0x100, and then
  0x1FF, and I added 0x101 to the mix too.

- Clean up logic in apm_console_blank().

- Prevent the error message from printing out twice.

Cc: Jordan Crouse <jordan.crouse@amd.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Provide basic support for the AMD Geode GX and LX processors.
Signed-off-by: NJordan Crouse <jordan.crouse@amd.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Removed the unused variable "rv".
Signed-off-by: NDaniel Marjamaki <daniel.marjamaki@comhem.se>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Removed the unused variable "rv".
Signed-off-by: NDaniel Marjamaki <daniel.marjamaki@comhem.se>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Missing newline in printk.
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The 'make rodata read-only' patch in -mm exposes a latent bug in the 32-bit
change_page_attr() function, which causes certain CPUs (Those with NX
basically) to reboot instantly after pages are marked read-only.

The same bug got fixed a while back on x86-64, but never got propagated to
i386.

Stuart Hayes from Dell also picked up on this last June, but it never got
fixed, as the only thing affected by it aparently was the nvidia driver.

Blatantly stealing description from his post..

"It doesn't appear to be fixed (in the i386 arch).  The
 change_page_attr()/split_large_page() code will still still set all the
 4K PTEs to PAGE_KERNEL (setting the _PAGE_NX bit) when a large page
 needs to be split.

 This wouldn't be a problem for the bulk of the kernel memory, but there
 are pages in the lower 4MB of memory that's free, and are part of large
 executable pages that also contain kernel code.  If change_page_attr()
 is called on these, it will set the _PAGE_NX bit on the whole 2MB region
 that was covered by the large page, causing a large chunk of kernel code
 to be non-executable."
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: <Stuart_Hayes@Dell.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If we are using hotplug enabled kernel, then make bigsmp the default mode.
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Allow SPARSEMEM to be enabled on non-numa x86 systems.  This is made
dependant on EXPERIMENTAL also being set.  When an in-tree user (such as
simulated numa) exists it should be made dependant on that.

The plan is to have no options and no selector as normal when
!EXPERIMENTAL.  When EXPERIMENTAL we enable the FLATMEM and SPARSEMEM
options for X86_PC whilst maintaining DISCONTIGMEM and SPARSEMEM for NUMA.
Signed-off-by: NAndy Whitcroft <apw@shadowen.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Mark some key kernel datastructures readonly.  This patch was previously
posted on Jun 28th but was back then not merged because nothing was enforcing
rodata anyway..  well that changed now :)

Patch by Christoph Lameter <christoph@lameter.com> and Dave Jones
<davej@redhat.com>
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

x86 specific parts to make the .rodata section read only
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove the "temporary debugging check" which has managed to live for quite
some time, and is clearly unneeded.  The mm can never be live at this point,
so clearly checking the LDT in the mm->context is redundant as well.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

APM BIOS code has a protective wrapper that runs it only on CPU zero.  Thus,
no need to set APM BIOS segments in the GDT for other CPUs.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Acked-by: N"Seth, Rohit" <rohit.seth@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Stop deleting NT bit from EFLAGS.  See arch/i386/kernel/head.S line 223, which
does something even better.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

PnP BIOS data, code, and 32-bit entry segments all have fixed limits as well;
set them in the GDT rather than adding more code.  It would be nice to add
these fixups to the boot GDT rather than setting the GDT for each CPU; perhaps
I can wiggle this in later, but getting it in before the subsys init looks
tricky.

Also, make some progress on deprecating the ugly Q_SET_SEL macros.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The one remaining caller of set_limit, the PnP BIOS code, calls into the PnP
BIOS, passing kernel parameters in and out.  These parameteres may be passed
from arbitrary kernel virtual memory, so they deserve strict protection to
stop a bad BIOS from smashing beyond the object size.

Unfortunately, the use of set_limit was badly botching this by setting the
limit in terms of pages, when it really should have byte granularity.

When doing this, I discovered my BIOS had the buggy code during the "get
system device node" call:

 mov ax, es:[bx]

Which is harmless, but has a trivial workaround.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Since APM BIOS segment limits are now fixed, set them in head.S GDT and don't
use the complicated _set_limit() macro expansion.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Acked-by: N"Seth, Rohit" <rohit.seth@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

APM BIOSes have many bugs regarding proper representation of the appropriate
segment limits for calling the BIOS.  By default, APM_RELAX_SEGMENTS is always
turned on to support running the APM BIOS on these buggy machines.  Keeping
64k limits poses very little danger to the kernel, because the pages where the
APM BIOS is located will always be in low physical memory BIOS areas, which
should already be marked reserved, and only buggy BIOSes would possibly
overstep the segment bounds with writes to data anyway.

Since forcing stricter limits breaks many machines and is not default
behavior, it seems reasonable to deprecate the older code which may cause APM
BIOS to fault.

If you really have a badly enough broken APM BIOS that you have to turn off
APM_RELAX_SEGMENTS, seems like the best recourse here would be to disable the
APM BIOS and / or not compile it into your kernel to begin with, and / or add
your system to the known bad list.

The reason I want to deprecate this code is there is underlying brokenness
with the set_limit macros, and getting rid of many of the call sites rather
than rewriting them seems to be the simplest and most correct course of
action.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Acked-by: N"Seth, Rohit" <rohit.seth@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

So some 486 processors do have CR4 register.  Allow them to present it in
register dumps by using the old fault technique rather than testing processor
family.

Thanks to Maciej for noticing this.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
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.
Acked-by: N"Seth, Rohit" <rohit.seth@intel.com>
Acked-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Move some code unrelated to any dealing with hardware bugs from i386's
bugs.h to a more logical place.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Rather than blindly re-enabling interrupts in die(), save their state
upon entry and then restore that state.

If the kernel is in really bad condition and faults with interrupts disabled,
re-enabling them in die() may cause even more trouble, implying more chances
of data corruption.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make GDT page aligned and page padded to support running inside of a
hypervisor.  This prevents false sharing of the GDT page with other hot
data, which is not allowed in Xen, and causes performance problems in
VMware.

Rather than go back to the old method of statically allocating the GDT
(which wastes unneded space for non-present CPUs), the GDT for APs is
allocated dynamically.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Setting RF (resume flag) allows a debugger to resume execution after a
code breakpoint without tripping the breakpoint again.  It is reset by
the CPU after execution of one instruction.

Requested by Stephane Eranian:
  "I am trying to the user HW debug registers on i386 and I am running
   into a problem with ptrace() not allowing access to EFLAGS_RF for
   POKEUSER (see FLAG_MASK).  [ ...  ] It avoids the need to remove the
   breakpoint, single step, and reinstall.  The equivalent functionality
   exists on IA-64 and is allowed by ptrace()"

Cc: Stephane Eranian <eranian@hpl.hp.com>
Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

According to the manual, INT 6 is "invalid opcode", not "invalid operand".
Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This should fix multi-threaded core-files

Signed-off-by: stsp@aknet.ru
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Now needs to include the type 1 functions ("direct") too.

Reported by Pavel Roskin <proski@gnu.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use correct address when referencing mmconfig aperture while checking
for broken MCFG.  This was a typo when porting the code from 64bit to
32bit.  It caused oopses at boot on some ThinkPads.

Should definitely go into 2.6.15.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

They report all busses as MMCONFIG capable, but it never works for the
internal devices in the CPU's builtin northbridge.

It just probes all func 0 devices on bus 0 (the internal northbridge is
currently always on bus 0) and if they are not accessible using MCFG they are
put into a special fallback bitmap.

On systems where it isn't we assume the BIOS vendor supplied correct MCFG.

Requires the earlier patch for mmconfig type1 fallback
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When there is no entry for a bus in MCFG fall back to type1.  This is
especially important on K8 systems where always some devices can't be accessed
using mmconfig (in particular the builtin northbridge doesn't support it for
its own devices)

Cc: <gregkh@suse.de>
Cc: <jgarzik@pobox.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It's illegal because it can sleep.

Use a two step lookup scheme instead.  First look up the vm_struct, then
change the direct mapping, then finally unmap it.  That's ok because nobody
can change the particular virtual address range as long as the vm_struct is
still in the global list.

Also added some LinuxDoc documentation to iounmap.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Disabling LAPIC timer isn't sufficient.  In some situations, such as we
enabled NMI watchdog, there is still unexpected interrupt (such as NMI)
invoked in offline CPU.  This also avoids offline CPU receives spurious
interrupt and anything similar.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Acked-by: N"Seth, Rohit" <rohit.seth@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When multiple probes are registered at the same address and if due to some
recursion (probe getting triggered within a probe handler), we skip calling
pre_handlers and just increment nmissed field.

The below patch make sure it walks the list for multiple probes case.
Without the below patch we get incorrect results of nmissed count for
multiple probe case.
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>

With CPU hotplug enabled, NMI watchdog stoped working.  It appears the
violation is the cpu_online check in nmi handler.  local ACPI based NMI
watchdog is initialized before we set CPU online for APs.  It's quite
possible a NMI is fired before we set CPU online, and that's what happens
here.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Acked-by: NZwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>