I realized ZONE_DMA32 has a trivial bug at Kconfig for ia64.  In
include/linux/gfp.h on 2.6.15-rc5-mm1, CONFIG is define like followings.

#ifdef CONFIG_DMA_IS_DMA32
#define __GFP_DMA32	((__force gfp_t)0x01)	/* ZONE_DMA is ZONE_DMA32
*/
       :
       :

So, CONFIG_"ZONE"_DMA_IS_DMA32 is clearly wrong.
Signed-off-by: NYasunori Goto <y-goto@jp.fujitsu.com>
Cc: "Luck, Tony" <tony.luck@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>

The patch that added support for a new platform chipset (shub2) broke
PTC deadlock recovery on older versions of the chipset. (PTCs are the
SN platform-specific method for doing a global TLB purge). This
patch fixes deadlock recovery so that it works on both the old & new
chipsets.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

We have a customer application which trips a bug.  The problem arises
when a driver attempts to call do_munmap on an area which is mapped, but
because current->thread.task_size has been set to 0xC0000000, the call
to do_munmap fails thinking it is an unmap beyond the user's address
space.

The comment in fs/binfmt_elf.c in load_elf_library() before the call
to SET_PERSONALITY() indicates that task_size must not be changed for
the running application until flush_thread, but is for ia64 executing
ia32 binaries.

This patch moves the setting of task_size from SET_PERSONALITY() to
flush_thread() as indicated.  The customer application no longer is able
to trip the bug.
Signed-off-by: NRobin Holt <holt@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The per-node data structures are allocated with strided offsets that are a
function of the node number. This prevents excessive cache-aliasing from
occurring.

On systems with a large number of nodes, the strided offset becomes
too large. This patch restricts the maximum offset to 32MB. This is far larger
than the size of any current L3 cache.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Altix only patch to add fixup code that sets up
pci_controller->window. This code is a temporary
fix until ACPI support on Altix is added.

Also, corrects the usage of pci_dev->sysdata,
which had previously been used to reference
platform specific device info, to now point to
a pci_controller struct.
Signed-off-by: NJohn Keller <jpk@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Return -EINTR instead of -ERESTARTSYS when signals are delivered during
a blocked read of /proc/sal/*/event.  This allows salinfo_decode to
detect signals when it is blocked on a read of those files.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Signed-off-by: NTony Luck <tony.luck@intel.com>

This updates the sn2_defconfig file for the Altix 330 hardware, enables
the AGP graphics for the SGI Prism, and removes prompts for the remainder
of the new features.  Greg Edwards reviewed the changes.
Signed-off-by: NRobin Holt <holt@sgi.com>
Signed-off-by: NGreg Edwards <edwardsg@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

break.b always sets cr.iim to 0 and the current code tries to
get the break_num by decoding instruction. However, their
seems to be a race condition while reading the regs->cr_iip,
as on other cpu the break.b at regs->cr_iip might have been
replaced with the original instruction as a result of
unregister_kprobe() and hence decoding instruction to
obtain break_num will result in wrong value in this case.

Also includes changes to kprobes.c which now has to handle
break number zero.
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

A single SGI Altix system can be divided into multiple partitions,
each running their own instance of the Linux kernel.  pfn_valid()
is currently not optimal for any but the first partition, since it
does not compare the pfn with min_low_pfn before calling the more
costly ia64_pfn_valid().
Signed-off-by: NDean Roe <roe@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Fix a bug in kprobes that can cause an Oops or even a crash when a return
probe is installed on one of the following functions: sys_execve,
do_execve, load_*_binary, flush_old_exec, or flush_thread.  The fix is to
remove the call to kprobe_flush_task() in flush_thread().  This fix has
been tested on all architectures for which the return-probes feature has
been implemented (i386, x86_64, ppc64, ia64).  Please apply.

BACKGROUND

Up to now, we have called kprobe_flush_task() under two situations: when a
task exits, and when it execs.  Flushing kretprobe_instances on exit is
correct because (a) do_exit() doesn't return, and (b) one or more
return-probed functions may be active when a task calls do_exit().  Neither
is the case for sys_execve() and its callees.

Initially, the mistaken call to kprobe_flush_task() on exec was harmless
because we put the "real" return address of each active probed function
back in the stack, just to be safe, when we recycled its
kretprobe_instance.  When support for ppc64 and ia64 was added, this safety
measure couldn't be employed, and was eventually dropped even for i386 and
x86_64.  sys_execve() and its callees were informally blacklisted for
return probes until this fix was developed.
Acked-by: NPrasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: NJim Keniston <jkenisto@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The nasid_index was not being incremented if the
pointer was null, causing an infinite loop.

Signed-off-by: Russ Anderson (rja@sgi.com)
Signed-off-by: NTony Luck <tony.luck@intel.com>

The kernel's use of the for_each_*cpu(i) macros has allowed for sparse CPU
numbering.  When I hacked the kernel to test sparse cpu_present_map[] and
cpu_possible_map[] cpumasks, I discovered one remaining spot, in
sn_hwperf_ioctl() during sn initialization, that needs to be fixed.
Signed-off-by: NJohn Hawkes <hawkes@sgi.com>
Signed-off-by: NDean Roe <roe@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Patch to prevent sn2_ptc_init code from attempting to load on non-sn2 systems
when sn2_smp.c is built-in to generic kernel.
Signed-off-by: NPrarit Bhargava <prarit@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Polish the comments specifically in vhpt_miss and nested_dtlb_miss
handlers.  I think it's better to explicitly name each page table
level with its name instead of numerically name them.  i.e., use
pgd, pud, pmd, and pte instead of referring as L1, L2, L3 etc.
Along the line, remove some magic number in the comments like:
"PTA + (((IFA(61,63) << 7) | IFA(33,39))*8)".  No code change at
all, pure comment update.  Feel free to shoot anything you have,
darts or tomahawk cruise missile.  I will duck behind a bunker ;-)
Signed-off-by: NKen Chen <kenneth.w.chen@intel.com>
Acked-by: NRobin Holt <holt@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

From source code inspection, I think there is a bug with 4 level
page table with vhpt_miss handler.  In the code path of rechecking
page table entry against previously read value after tlb insertion,
*pte value in register r18 was overwritten with value newly read
from pud pointer, render the check of new *pte against previous
*pte completely wrong.  Though the bug is none fatal and the penalty
is to purge the entry and retry.  For functional correctness, it
should be fixed.  The fix is to use a different register so new
*pud don't trash *pte.  (btw, the comments in the cmp statement is
wrong as well, which I will address in the next patch).
Signed-off-by: NKen Chen <kenneth.w.chen@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Our performance validation on 2.6.15-rc1 caught a disastrous performance
regression on ia64 with netperf (-98%) and volanomark (-58%) compares to
previous kernel version 2.6.14-git7.  See the following chart (result
group 1 & 2).

  http://kernel-perf.sourceforge.net/results.machine_id=26.html

We have root caused it to commit 64c7c8f8

This changeset broke the ia64 task resched notification.  In
sched.c:resched_task(), a reschedule IPI is conditioned upon
TIF_POLLING_NRFLAG.  However, the above changeset unconditionally set
the polling thread flag for idle tasks regardless whether pal_halt_light
is in use or not.  As a result, resched IPI is not sent from
resched_task().  And since the default behavior on ia64 is to use
pal_halt_light, we end up delaying the rescheduling task until next
timer tick, and thus cause the performance regression.

This fixes the performance bug.  I'm glad our performance suite is
turning up bad performance bug like this in time.
Signed-off-by: NKen Chen <kenneth.w.chen@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

IA64 traditionally had a 4GB DMA32 zone. Set the compatibility flag
to keep old drivers working.

For new drivers it would be better to use ZONE_DMA32 now.

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

Fix default VGA console on SN platforms.  Since SN firmware does not pass
enough ACPI information to identify VGA cards and the associated legacy IO/MEM
addresses, we rely on the EFI PCDP table.  Since the linux pcdp driver is
optional (and overridden if console= directives are used) SN duplicates a
portion of the pcdp scan code to identify if there is a usable console VGA
adapter.  Additionally, dup necessary pcdp related structs to avoid dragging
drivers/pcdp.h into a more public location.
Signed-off-by: NMark Maule <maule@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

This patch introduces 4-level page tables to ia64.  I have run
some benchmarks and found nothing interesting.  Performance has
consistently fallen within the noise range.

It also introduces a config option (setting the default to 3
levels).  The config option prevents having 4 level page
tables with 64k base page size.
Signed-off-by: NRobin Holt <holt@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

XPC (as in arch/ia64/sn/kernel/xp*) has a need to notify other partitions
(SGI Altix) whenever a partition is going down in order to get them to
disengage from accessing the halting partition's memory. If this is not
done before the reset of the hardware, the other partitions can find
themselves encountering MCAs that bring them down.
Signed-off-by: NDean Nelson <dcn@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Conversion from kcalloc(1, to kzalloc.
Signed-off-by: NPanagiotis Issaris <takis@issaris.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce
confusion, and make their semantics rigid.  Improves efficiency of
resched_task and some cpu_idle routines.

* In resched_task:
- TIF_NEED_RESCHED is only cleared with the task's runqueue lock held,
  and as we hold it during resched_task, then there is no need for an
  atomic test and set there. The only other time this should be set is
  when the task's quantum expires, in the timer interrupt - this is
  protected against because the rq lock is irq-safe.

- If TIF_NEED_RESCHED is set, then we don't need to do anything. It
  won't get unset until the task get's schedule()d off.

- If we are running on the same CPU as the task we resched, then set
  TIF_NEED_RESCHED and no further action is required.

- If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set
  after TIF_NEED_RESCHED has been set, then we need to send an IPI.

Using these rules, we are able to remove the test and set operation in
resched_task, and make clear the previously vague semantics of
POLLING_NRFLAG.

* In idle routines:
- Enter cpu_idle with preempt disabled. When the need_resched() condition
  becomes true, explicitly call schedule(). This makes things a bit clearer
  (IMO), but haven't updated all architectures yet.

- Many do a test and clear of TIF_NEED_RESCHED for some reason. According
  to the resched_task rules, this isn't needed (and actually breaks the
  assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock
  held). So remove that. Generally one less locked memory op when switching
  to the idle thread.

- Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner
  most polling idle loops. The above resched_task semantics allow it to be
  set until before the last time need_resched() is checked before going into
  a halt requiring interrupt wakeup.

  Many idle routines simply never enter such a halt, and so POLLING_NRFLAG
  can be always left set, completely eliminating resched IPIs when rescheduling
  the idle task.

  POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Con Kolivas <kernel@kolivas.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Run idle threads with preempt disabled.

Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
How did it ever work before?

Might fix the CPU hotplugging hang which Nigel Cunningham noted.

We think the bug hits if the idle thread is preempted after checking
need_resched() and before going to sleep, then the CPU offlined.

After calling stop_machine_run, the CPU eventually returns from preemption and
into the idle thread and goes to sleep.  The CPU will continue executing
previous idle and have no chance to call play_dead.

By disabling preemption until we are ready to explicitly schedule, this bug is
fixed and the idle threads generally become more robust.

From: alexs <ashepard@u.washington.edu>

  PPC build fix

From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>

  MIPS build fix
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NYoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Some architectures define and use this type in their compat_ioctl code, but
all of them can easily use the identical ioctl_trans_handler_t type that is
defined in common code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

ia64 translates normal loads and stores to special MMIO regions into I/O port
accesses.  Reserve these special MMIO regions in /proc/iomem.

Sample /proc/iomem:
    f8100000000-f81003fffff : PCI Bus 0000:80 I/O Ports 00000000-00000fff
    f8100400000-f81007fffff : PCI Bus 0000:8e I/O Ports 00001000-00001fff
    f8100800000-f8100ffffff : PCI Bus 0000:9c I/O Ports 00002000-00003fff
    f8101000000-f81017fffff : PCI Bus 0000:aa I/O Ports 00004000-00005fff

and corresponding /proc/ioports:
    00000000-00000fff : PCI Bus 0000:80
    00001000-00001fff : PCI Bus 0000:8e
    00002000-00003fff : PCI Bus 0000:9c
    00004000-00005fff : PCI Bus 0000:aa
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Fix a couple of altix interrupt related bugs.
Signed-off-by: NMark Maule <maule@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

When a page has a memory uncorrectable ECC error, the recovery
code wants to prevent the page from being reused.  This change
bumps the reference count to prevent the page from getting back
on the free list.

Signed-off-by: Russ Anderson (rja@sgi.com)
Signed-off-by: NTony Luck <tony.luck@intel.com>

paddr needs to be shifted by PAGE_SHIFT to be valid
input for pfn_valid().
Signed-off-by: NRuss Anderson <rja@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The determination of whether an MCA is recoverable or not must
be based on the bits set in the PSP (Processor State Parameter).
The specific bits are shown in the Intel IA-64 Architecture Software
Developer's Manual, Vol 2, Table 11-6 Software Recovery Bits in
Processor State Parameter.  Those bits should be consistent
across the entire IA-64 family of processors.
Signed-off-by: NRuss Anderson <rja@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

At the moment, attempting to invoke a signal-handler on the normal
stack is guaranteed to fail if the stack-pointer happens not to be
16-byte aligned.  This is because the signal-trampoline will attempt
to store fp-regs with stf.spill instructions, which will trap for
misaligned addresses.  This isn't terribly useful behavior.  It's
better to just always align the signal frame to the next lower 16-byte
boundary.
Signed-off-by: NDavid Mosberger-Tang <David.Mosberger@acm.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The original memory less node allocation attempted to use NODEDATA_ALIGN for
alignment.  The bootmem allocator only allows a power of two alignments. This
causes a BUG_ON for some nodes. For cpu only nodes just allocate with a
PERCPU_PAGE_SIZE alignment.

Some older firmware reports SLIT distances of 0xff and results in bestnode
not being computed. This is now treated correctly.

The failed allocation check was removed because it's redundant.  The
bootmem allocator already makes this check.

This fix has been boot tested on 4 node machine which has 4 cpu only nodes
and 1 memory node.  Thanks to Pete Keilty for reporting this and helping me
test it.
Signed-off-by: NBob Picco <bob.picco@hp.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

notify_die() added for MCA_{MONARCH,SLAVE,RENDEZVOUS}_{ENTER,PROCESS,LEAVE} and
INIT_{MONARCH,SLAVE}_{ENTER,PROCESS,LEAVE}.  We need multiple
notification points for these events because they can take many seconds
to run which has nasty effects on the behaviour of the rest of the
system.

DIE_SS replaced by a generic DIE_FAULT which checks the vector number,
to allow interception of faults other than SS.

DIE_MACHINE_{HALT,RESTART} added to allow last minute close down
processing, especially when the halt/restart routines are called from
error handlers.

DIE_OOPS added.

The check for kprobe's break numbers has been moved from traps.c to
kprobes.c, allowing DIE_BREAK to be used for any additional break
numbers, i.e. it is no longer kprobes specific.

Hooks for kernel debuggers and kernel dumpers added, ENTER and LEAVE.
Both of these disable the system for long periods which impact on
watchdogs and heartbeat systems in general.  More patches to come that
use these events to reset watchdogs and heartbeats.

unregister_die_notifier() added and both routines exported.  Requested
by Dean Nelson.

Lock removed from {un,}register_die_notifier.  notifier_chain_register()
already takes a lock.  Also the generic notifier chain locking is being
reworked to distinguish between callbacks that can block and those that
cannot, the lock in {un,}register_die_notifier would interfere with
that change.  http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2

Leading white space removed from arch/ia64/kernel/kprobes.c.

Typo in mca.c in original version of this patch found & fixed by Dean
Nelson.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Acked-by: NDean Nelson <dcn@sgi.com>
Acked-by: NAnil Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

This is the arch/ part of the big kfree cleanup patch.

Remove pointless checks for NULL prior to calling kfree() in arch/.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Acked-by: NGrant Grundler <grundler@parisc-linux.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use schedule_timeout_interruptible() instead of
set_current_state()/schedule_timeout() to reduce kernel size.
Signed-off-by: NNishanth Aravamudan <nacc@us.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Reorganize the preempt_disable/enable calls to eliminate the extra preempt
depth.  Changes based on Paul McKenney's review suggestions for the kprobes
RCU changeset.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
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>

Changes to the arch kprobes infrastructure to take advantage of the locking
changes introduced by usage of RCU for synchronization.  All handlers are now
run without any locks held, so they have to be re-entrant or provide their own
synchronization.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
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>

IA64 changes to track kprobe execution on a per-cpu basis.  We now track the
kprobe state machine independently on each cpu using an arch specific kprobe
control block.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
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 set of patches are aimed at improving kprobes scalability.  We
currently serialize kprobe registration, unregistration and handler execution
using a single spinlock - kprobe_lock.

With these changes, kprobe handlers can run without any locks held.  It also
allows for simultaneous kprobe handler executions on different processors as
we now track kprobe execution on a per processor basis.  It is now necessary
that the handlers be re-entrant since handlers can run concurrently on
multiple processors.

All changes have been tested on i386, ia64, ppc64 and x86_64, while sparc64
has been compile tested only.

The patches can be viewed as 3 logical chunks:

patch 1: 	Reorder preempt_(dis/en)able calls
patches 2-7: 	Introduce per_cpu data areas to track kprobe execution
patches 8-9: 	Use RCU to synchronize kprobe (un)registration and handler
		execution.

Thanks to Maneesh Soni, James Keniston and Anil Keshavamurthy for their
review and suggestions. Thanks again to Anil, Hien Nguyen and Kevin Stafford
for testing the patches.

This patch:

Reorder preempt_disable/enable() calls in arch kprobes files in preparation to
introduce locking changes.  No functional changes introduced by this patch.
Signed-off-by: NAnanth N Mavinakayahanalli <ananth@in.ibm.com>
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>