This patch fixes a race condition where in system used to hang or sometime
crash within minutes when kprobes are inserted on ISR routine and a task
routine.

The fix has been stress tested on i386, ia64, pp64 and on x86_64.  To
reproduce the problem insert kprobes on schedule() and do_IRQ() functions
and you should see hang or system crash.
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: NPrasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch addresses a potential race condition for a case where Kprobe has
been removed right after another CPU has taken a break hit.

The way this is addressed here is when the CPU that has taken a break hit
does not find its corresponding kprobe, then we check to see if the
original instruction got replaced with other than break.  If it got
replaced with other than break instruction, then we continue to execute
from the replaced instruction, else if we find that it is still a break,
then we let the kernel handle this, as this might be the break instruction
inserted by other than kprobe(may be kernel debugger).
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>

This patch contains the ia64 architecture specific changes to prevent the
possible race conditions.
Signed-off-by: NPrasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch converts kcalloc(1, ...) calls to use the new kzalloc() function.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

64 bit architectures all implement their own compatibility sys_open(),
when in fact the difference is simply not forcing the O_LARGEFILE
flag.  So use the a common function instead.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Cc: <viro@parcelfarce.linux.theplanet.co.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NJohn Hawkes <hawkes@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I've already sent this to the maintainers, and this is now being sent to a
larger community audience.  I have fixed a problem with the ia64 version of
build_sched_domains(), but a similar fix still needs to be made to the
generic build_sched_domains() in kernel/sched.c.

The "dynamic sched domains" functionality has recently been merged into
2.6.13-rcN that sees the dynamic declaration of a cpu-exclusive (a.k.a.
"isolated") cpuset and rebuilds the CPU Scheduler sched domains and sched
groups to separate away the CPUs in this cpu-exclusive cpuset from the
remainder of the non-isolated CPUs.  This allows the non-isolated CPUs to
completely ignore the isolated CPUs when doing load-balancing.

Unfortunately, build_sched_domains() expects that a sched domain will
include all the CPUs of each node in the domain, i.e., that no node will
belong in both an isolated cpuset and a non-isolated cpuset.  Declaring a
cpuset that violates this presumption will produce flawed data structures
and will oops the kernel.

To trigger the problem (on a NUMA system with >1 CPUs per node):
   cd /dev/cpuset
   mkdir newcpuset
   cd newcpuset
   echo 0 >cpus
   echo 0 >mems
   echo 1 >cpu_exclusive

I have fixed this shortcoming for ia64 NUMA (with multiple CPUs per node).
A similar shortcoming exists in the generic build_sched_domains() (in
kernel/sched.c) for NUMA, and that needs to be fixed also.  The fix
involves dynamically allocating sched_group_nodes[] and
sched_group_allnodes[] for each invocation of build_sched_domains(), rather
than using global arrays for these structures.  Care must be taken to
remember kmalloc() addresses so that arch_destroy_sched_domains() can
properly kfree() the new dynamic structures.
Signed-off-by: NJohn Hawkes <hawkes@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When handling writes to /proc/irq, current code is re-programming rte
entries directly. This is not recommended and could potentially cause
chipset's to lockup, or cause missing interrupts.

CONFIG_IRQ_BALANCE does this correctly, where it re-programs only when the
interrupt is pending. The same needs to be done for /proc/irq handling as well.
Otherwise user space irq balancers are really not doing the right thing.

- Changed pending_irq_balance_cpumask to pending_irq_migrate_cpumask for
  lack of a generic name.
- added move_irq out of IRQ_BALANCE, and added this same to X86_64
- Added new proc handler for write, so we can do deferred write at irq
  handling time.
- Display of /proc/irq/XX/smp_affinity used to display CPU_MASKALL, instead
  it now shows only active cpu masks, or exactly what was set.
- Provided a common move_irq implementation, instead of duplicating
  when using generic irq framework.

Tested on i386/x86_64 and ia64 with CONFIG_PCI_MSI turned on and off.
Tested UP builds as well.

MSI testing: tbd: I have cards, need to look for a x-over cable, although I
did test an earlier version of this patch.  Will test in a couple days.
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
Acked-by: NZwane Mwaikambo <zwane@holomorphy.com>
Grudgingly-acked-by: NAndi Kleen <ak@muc.de>
Signed-off-by: NCoywolf Qi Hunt <coywolf@lovecn.org>
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Change sn2-specific calls into generic functions.  Without this change
the uncached allocator will not work on non-sn2 platforms.
Signed-off-by: NGreg Edwards <edwardsg@sgi.com>
Signed-off-by: NMartin Hicks <mort@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

It has been reported that the way Linux handles NODEFER for signals is
not consistent with the way other Unix boxes handle it.  I've written a
program to test the behavior of how this flag affects signals and had
several reports from people who ran this on various Unix boxes,
confirming that Linux seems to be unique on the way this is handled.

The way NODEFER affects signals on other Unix boxes is as follows:

1) If NODEFER is set, other signals in sa_mask are still blocked.

2) If NODEFER is set and the signal is in sa_mask, then the signal is
still blocked. (Note: this is the behavior of all tested but Linux _and_
NetBSD 2.0 *).

The way NODEFER affects signals on Linux:

1) If NODEFER is set, other signals are _not_ blocked regardless of
sa_mask (Even NetBSD doesn't do this).

2) If NODEFER is set and the signal is in sa_mask, then the signal being
handled is not blocked.

The patch converts signal handling in all current Linux architectures to
the way most Unix boxes work.

Unix boxes that were tested:  DU4, AIX 5.2, Irix 6.5, NetBSD 2.0, SFU
3.5 on WinXP, AIX 5.3, Mac OSX, and of course Linux 2.6.13-rcX.

* NetBSD was the only other Unix to behave like Linux on point #2. The
main concern was brought up by point #1 which even NetBSD isn't like
Linux.  So with this patch, we leave NetBSD as the lonely one that
behaves differently here with #2.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

copy_page.o appeared twice in arch/ia64/lib/Makefile. The
one in global lib-y is wrong where it should be just in
lib-$(CONFIG_ITANIUM).

Both copy_page.o and copy_page_mck.o are build for Itanium2
processor and the link order will pick up the low performing
copy_page function (originally written for itanium processor).
In this case, we really want the copy_page_mck.o for optimized
version.
Signed-off-by: NKenneth Chen <kenneth.w.chen@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Patch to support P-state transitions on ia64. This driver is based on ACPI,
and uses the ACPI processor driver interface to find out the P-state support
information for the processor. This driver plugs into generic cpufreq
infrastructure.

Once this driver is loaded successfully, ondemand/userspace governor can be
used to change the CPU frequency dynamically based on load or on request from
userspace process.

Refer :
ACPI specification -
      http://www.acpi.info
P-state related PAL calls -
      http://developer.intel.com/design/itanium/downloads/24869909.pdfSigned-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

bte_copy() calls calls smp_processor_id(), which will get flagged if
preemption if enabled.  raw_smp_processor_id() is used instead 
because we are just using it to pick a BTE interface and are not 
tied to a specific cpu.

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

Altix patch to abstract irq_affinity down to the pci provider level since
different SGI hardware implements this in different ways.
Signed-off-by: NMark Maule <maule@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Clean up of SGI SN partitioning related code.
The SN_SAL_GET_SN_INFO SAL call returns the partition ID, making
the SN_SAL_SYSCTL_PARTITION_GET SAL call redundant.  Remove sn_partid
and use sn_partition_id.

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

Update the SN pci device info to use the nearest node function
to allocate driver memory on the nearest node (rather than
defaulting to node 0).
Signed-off-by: NMark Goodwin <markgw@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Add a new exported function for determining the nearest node
with CPUs for I/O nodes and fix a bug where the hwperf dynamic
misc device was being registered before misc_init(). 
Signed-off-by: NMark Goodwin <markgw@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Bugfix to export PCI topology information in /proc/sgi_sn/sn_topology.
Signed-off-by: NMark Goodwin <markgw@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Currently, region numbers are defined in several files, with several 
names.  For example, we have REGION_KERNEL in asm/page.h and 
RGN_KERNEL in pgtable.h 
 
We also have address definitions that should depend on the 
RGN_XXX macros, but are currently just long constants. 
 
The following patch reorganises all the definitions so that they have 
the same form (RGN_XXX), are in one place, and that addresses that 
depend on RGN_XXX are derived from them. 

(This is a necessary but not sufficient patch to allow UML-like 
operation on IA64). 

Thanks to David Mosberger for catching the change I missed in mmu_context.h.
 
Signed-off-by: Peter Chubb <peterc@gelato.unsw.edu.au> 
Signed-off-by: NTony Luck <tony.luck@intel.com>

Kernel 2.6 doesn't support egcs, and I didn't find any user of this 
function.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Removed IA64 architecture specific users of asm/segment.h
The removal of asm-ia64/segment.h itself can wait until all
of the kernel source has been purged of references.
Signed-off-by: NKumar Gala <kumar.gala@freescale.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

pcibios_bus_to_resource is exported on all architectures except ia64
and sparc.  Add exports for the two missing architectures.  Needed when
Yenta socket support is compiled as a module.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Thanks to Stephane, we've now worked out the real cause of the
`Linux  will not boot on simulator' problem.  Turns out it's a stack
overflow because the stack pointer wasn't being initialised properly
in boot_head.S (it was being initialised to the lowest instead of the
highest address of the stack, so the first push started to overwrite
data in the BSS).
Signed-off-by: NPeter Chubb <peterc@gelato.unsw.edu.au>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Earlier fix in 4aec0fb1 just
masked the real problem.
Signed-off-by: NTony Luck <tony.luck@intel.com>

   Fix swiotlb sizing to match what the comments and the kernel
parameters documentation indicate.  Given a default 16k page size kernel
(ia64) and a 2k swiotlb page size, we're off by a multiple of 8 trying
to size the swiotlb.  When specified on the boot line, the swiotlb is
made 8x bigger than requested.  When left to the default value, it's 8x
smaller than the comments indicate.  For x86_64 the multiplier would be
2x.  The patch below fixes this.  Now, what's a good default swiotlb
size?  Apparently we don't really need 64MB.
Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

After building a fresh tree with gcc 4 I can't boot the simulator as
the bootloader loader dies with 

loading /home/ianw/kerntest/kerncomp//build/sim_defconfig/vmlinux...
failed to read phdr

After some investigation I believe this is do with differences between
the alignment of variables on the stack between gcc 3 and 4 and the
ski simulator.  If you trace through with the simulator you can see
that the disk_stat structure value returned from the SSC_WAIT_COMPLETION
call seems to be only half loaded.  I guess it doesn't like the alignment
of the input.
Signed-off-by: NIan Wienand <ianw@gelato.unsw.edu.au>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Shub2 provides a much improved mechanism for issuing internode
TLB purges. Add code to support the newer mechanism. There is also 
some debug code (disabled) that is useful for testing.

Collect statistics on the number, type & duration of TLB purges.
This data will be useful for making future improvements in the algorithms.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Add a few missing calls to "hint @pause".
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Change the BTE driver so that it works for both shub1 and
shub2. Most of the changes are related to the number of cores
that use the BTE engine, to the MMR addresses of various
shub registers, and to using the correct processor or network
physical address.
Signed-off-by: NRuss Anderson <rja@sgi.com>
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Disable some shub1-specific code when running on systems with shub2.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Update the addresses of the pio_write_status_addr so that
they are correct for newer processors. Shub2 did not number
the threads in the order that I had expected.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Use local SHUB alias space when referencing MMRs that are known
to be node local. There is a slight performance benefit & code 
simplification.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

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

Just `make oldconfig' doesn't help for the zx1 defconfig ---
because we need the MPT Fusion drivers, which are picked up as not
selected.
Tested on HP ZX2000 and ZX2600.
Signed-off-by: NPeter Chubb <peterc@gelato.unsw.edu.au>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Signed-off-by: NGreg Edwards <edwardsg@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Some IA64 spinlocks are not being initialized, make it so.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The main issue is that bus_fixup calls may potentially call
functions that require a valid bus->sysdata pointer.  Since
this is the case, we must set the bus->sysdata pointer before
calling the bus_fixup functions.  The remaining changes are
simple fixes to make sure memory is cleaned up in the function.
Signed-off-by: NPrarit Bhargava <prarit@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Fix for ia64 sched domain building triggered by cpuset code.
Acked-by: NNick Piggin <npiggin@suse.de>
Acked-by: NDinakar Guniguntala <dino@in.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The current one doesn't even make sense anymore on i386 where it
apparently came from.

Follow-up wordsmithing by Matthew Wilcox and Tony Luck.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Altix patch to add an SN pci provider for TIOCE, which is SGI's 
PCI Express implementation.
Signed-off-by: NMark Maule <maule@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>