ia64: NR_CPUS and number of CPUs

While building a kernel for our 4-way Lion box, I made the
mistake of setting NR_CPUS to 4.  Little did I know that the
Lion ACPI tables always list 8 CPUs (with only the first N
enabled), and so the resulting kernel overflowed the
smp_boot_data.cpu_phys_id array, crashed and burned.

fp assist.  The problem lies with concurrent, potentially frequent
updates of fpu_swa_count, which serves as the throttle for doing the
printk().  A frenzy of concurrent updates will produce a frenzy of
cacheline ping-ponging.

The fix is simple:

Only increment fpu_swa_count when the printk() is about to happen,
which limits the increment to no more than four times every five
seconds.

  ia64: no perfmon 2.5 fix

  ia64: cleaning up the INIT code

	In particular, this fixes a panic() in the IDE code which
	triggered on machines with IDE disks and memory above
	4GB.

	can escape include-hell.

This patch contains a major rewrite of the perfmon subsystem to
bring it to version 2.0. This version is NOT compatible with the
existing perfmon-1.x version which was in 2.5 and still is in 2.4
kernels. This new codebase brings a lot of new features including
the ability to attach to already running tasks, the ability the
follow clone2, the ability to write your own sampling buffer format
via kernel modules. It is also much more robust than its 1.x
counter-part. This version supports the Itanium, McKinley and
Madison PMUs. This is beta quality code and extensions to the
interface are planned.

Make the size of the user stack based on the stack rlimit.
The stack hard stack size now defaults to 2GB, but can be increased
 with ulimit up to 1/2 of the max mappable space in a region.
For 16k pages, this makes the max stack size 8TB.

I was getting annoyed at having to mess around with the HP Simulator
stuff when trying to compile generic kernels.  Here's the fix that I
came up with.  It basically makes the HP Sim console another config
option that depends on the HP sim serial code.

It also sticks a couple of run-time checks in the init functions to only
setup and run the code on hpsim machines.

This is a 2.5 version of the patch that I juggled around a couple of
weeks ago.  It's just a simple macro that allows one to check if the
kernel is running on a specific ia64 platform.

	left-over bits from the old task-creation/destruction hacks.  Fix typo
	in comment for pgprot_noncached().

	infrastructure.

	necessary.

The syscall optimization patches broke the OS INIT handler because
SAVE_RESET was addressing relative to r12, which contains the virtual
address of the stack pointer.  Fixed by addressing relative to r2/r3
instead.

Please find the attached patch that:

1. Moves user stack flag memory access before srlz.i;

2. Moves mov b6=r22 as late as possible. 

3. Changes (pSys) to (pLvSys) in skip_rbs_switch: section. IA32 syscall
set pSys=1 but pLvSys=0. It's not necessary to clear bank1 r16-r19 registers
for IA32 syscall.

The number for leave_syscall is 268 cycles with this patch. The number
is 295 cycles w/o this patch. It was 245 cycles with the original kee patched
kernel. The 23 cycles come from restoring b6 operation which didn't exist in
the orignal kee patch.

Only call get_scratch_regs() when pt is really needed.  The extraneous
calls to get_scratch_regs() can otherwise pick up the wrong address for pt.
For example, calling unw_access_ar(&info, UNW_AR_BSPSTORE,...) before pt_regs
had been reached could trigger this bug.

A bug-fix in IA-32 emulation ptrace code. The bug originally got
introduced with the addition of FPXREGS support in ptrace.

The bug is in ptrace get/set FPREGS routine. gdb by default will not use
FPREGS routines when FPXREGS routines are supported.  So we may not see
this bug during normal gdb operations. But, if gdb (or any other app)
directly tries to get/set FPREGS (probably an old version of gdb), it
will end with an segmentation fault due to this bug.

Attached patch fixes the issue. The patch is taken against 2.5.69. But
it applies to 2.4 tree as well.

the first patch  moves some definitions
out of perfmon.c to perfmon.h (similar to what is in 2.4). 

The second patch contains a fix for the generic built. I did 
it that way to avoid other problems such as SIMSCSI depends
on SCSI. so simply hardcoding this in the MAkefile could cause
other problems. Anyway, SIMSCI is not defaulting to y when
HP_SIM is defined so it is not so different.

Attached is a patch for interleaved discontigmem banks.

When memory banks are interleaved between nodes,
bank ids can be overwritten by other nodes.

I was building 2.5 and noticed that if you have raid5 configured as
a module, then the arch/ia64/lib/xor.S would not get built (gets a
make error since c file not there).

Attached patch fixes that so xor.S gets built if raid5 is built-in
or a module.

We need sometimes to load the physical address of a kernel
object.  Often we can convert the virtual address to physical
at execution time, but sometimes (either for performance reasons
or during error recovery) we cannot to this.  Patch the marked
bundles to load the physical address.

	kernel patch.  This patch makes it work again.  The MCA path is
	similarly broken.  Patch will follow later.

  Delete: arch/ia64/tools/print_offsets.awk
.del-Makefile~90bde6a95198c56c:
  Delete: arch/ia64/tools/Makefile

Delete references to arch/ia64/tools; use standard sed script to generate
offsets.h.

This gets the dependencies right for offsets.h

	run faster than break-based syscall stubs, even if there is
	no light-weight syscall handler.
	Adds a new boot command-line option "nolwsys" which can be used
	to turn off light-weight system call handlers.  Good for
	performance measurement and (potentially) for debugging.

	signals corrupting r14.

	fix bit rot in signal debug printk.

	Instead of using break, this one bubbles down into the kernel
	directly.  This code works, but isn't performance optimal yet.

	didn't preserve b6 and r11 anymore.  Unfortunately, preserving them costs
	a few cycles (~5 cycles in the cached case).  The uncached case is hopefully
	mostly unaffected because the number of cache-lines touched is the same
	(without preserving b6 and r11, the entry-patch _almost_ got away with
	touching a single 128-byte cacheline, but not quite, because r8 also
	had to be initialized).

	now cleared by the syscall exit path.

	whitespace changes only.

	Fix setting of current->thread.on_ustack flag in optimized syscall exit path.
	Tune break_fault for syscall execution.
	Break ia32_execve: the ia64_execve() hack that was there is too ugly for
	words; surely we can do better...

Here's another sn2 update.  It includes a bunch of misc. bits:
  o a bunch of cleanup from hch
  o addition of DMA routine wrappers
  o update of other PCI routines
  o topology.h prototype addition.

This should get the CONFIG_PREEMPT to work again.  We were trashing
r20 by accident.