Making a variable page-aligned by using
__attribute__((section(".data.page_aligned"))) is fragile because if
sizeof(variable) is not also a multiple of page size, it leaves
variables in the remainder of the section unaligned.

This patch introduces two new qualifiers, __page_aligned_data and
__page_aligned_bss to set the section *and* the alignment of
variables.  This makes page-aligned variables more robust because the
linker will make sure they're aligned properly.  Unfortunately it
requires *all* page-aligned data to use these macros...
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch moves the reserve_crashkernel() to setup.c and removes the
architecture-specific version. Both versions were more or less the same.

I tested it on both x86-64 and i386, with CONFIG_KEXEC on and off (so
that it compiles).
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Cc: yhlu.kernel@gmail.com
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Conflicts:

	arch/x86/mm/init_64.c
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Someone could write 0 bytes to /proc/sgi_uv/ptc_statistics,
causing
  optstr[count - 1] = '\0';
to write to who-knows-where.

(Andi Kleen noticed this need from a patch I sent for
 similar code in the ia64 world (sn2_ptc_proc_write()).)

(count less than zero is not possible here, as count is unsigned)
Signed-off-by: NCliff Wickman <cpw@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

v6: 6/19 close the security hole in uv_ptc_proc_write())

  > Found a potential security hole while doing that:
  > static ssize_t uv_ptc_proc_write(struct file *file, const char __user *user,
  >                              size_t count, loff_t *data)
  >     if (copy_from_user(optstr, user, count))
  >             return -EFAULT;
  >
  > is count guaranteed to never be larger than 64?

is fixed below.

It adds tlb_uv.o to the Makefile.
Signed-off-by: NCliff Wickman <cpw@sgi.com>
Cc: mingo@elte.hu
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Increase the maximum number of apics when running very large
configurations. This patch has no affect on most systems.

The patch has no effect on any 32-bit kernel. It adds ~4k to the size
of 64-bit kernels but only if NR_CPUS > 255.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

physid_mask_of_physid() causes a huge stack (12k) to be created if the
number of APICS is large. Replace physid_mask_of_physid() with a
new function that does not create large stacks. This is a problem only
on large x86_64 systems.

this paves the way to increase MAX_APICS.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Cc: linux-mm@kvack.org
Cc: mingo@elte.hu
Cc: tglx@linutronix.de
Signed-off-by: NIngo Molnar <mingo@elte.hu>

fix:

arch/x86/kernel/tlb_uv.c: In function ‘uv_table_bases_init':
arch/x86/kernel/tlb_uv.c:612: error: ‘bau_tabsp' undeclared (first use in this function)
arch/x86/kernel/tlb_uv.c:612: error: (Each undeclared identifier is reported only once
arch/x86/kernel/tlb_uv.c:612: error: for each function it appears in.)
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NIngo Molnar <mingo@elte.hu>

TLB shootdown for SGI UV.

v5: 6/12 corrections/improvements per Ingo's second review
Signed-off-by: NCliff Wickman <cpw@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

TLB shootdown for SGI UV.

v1: 6/2 original
v2: 6/3 corrections/improvements per Ingo's review
v3: 6/4 split atomic operations off to a separate patch (Jeremy's review)
v4: 6/12 include <mach_apic.h> rather than <asm/mach-bigsmp/mach_apic.h>
         (fixes a !SMP build problem that Ingo found)
         fix the index on uv_table_bases[blade]
Signed-off-by: NCliff Wickman <cpw@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Provide atomic operations for increment of a 16-bit integer and
logical OR into a 64-bit integer.
Signed-off-by: NCliff Wickman <cpw@sgi.com>
Reviewed-by: NJeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

TLB shootdown for SGI UV.

Depends on patch (in tip/x86/irq):
   x86-update-macros-used-by-uv-platform.patch   Jack Steiner May 29

This patch provides the ability to flush TLB's in cpu's that are not on
the local node.  The hardware mechanism for distributing the flush
messages is the UV's "broadcast assist unit".

The hook to intercept TLB shootdown requests is a 2-line change to
native_flush_tlb_others() (arch/x86/kernel/tlb_64.c).

This code has been tested on a hardware simulator. The real hardware
is not yet available.

The shootdown statistics are provided through /proc/sgi_uv/ptc_statistics.
The use of /sys was considered, but would have required the use of
many /sys files.  The debugfs was also considered, but these statistics
should be available on an ongoing basis, not just for debugging.

Issues to be fixed later:
- The IRQ for the messaging interrupt is currently hardcoded as 200
  (see UV_BAU_MESSAGE).  It should be dynamically assigned in the future.
- The use of appropriate udelay()'s is untested, as they are a problem
  in the simulator.
Signed-off-by: NCliff Wickman <cpw@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Conflicts:

	arch/x86/kernel/nmi.c
	arch/x86/kernel/nmi_32.c
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Conflicts:

	arch/x86/Kconfig
	arch/x86/kernel/e820.c
	arch/x86/kernel/efi_64.c
	arch/x86/kernel/mpparse.c
	arch/x86/kernel/setup.c
	arch/x86/kernel/setup_32.c
	arch/x86/mm/init_64.c
	include/asm-x86/proto.h
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch uses reserve_bootmem_generic() instead of reserve_bootmem()
to reserve the crashkernel memory on x86_64. That's necessary for NUMA
machines, see 00212fef:

  [PATCH] Fix kdump Crash Kernel boot memory reservation for NUMA machines

  This patch will fix a boot memory reservation bug that trashes memory on
  the ES7000 when loading the kdump crash kernel.

  The code in arch/x86_64/kernel/setup.c to reserve boot memory for the crash
  kernel uses the non-numa aware "reserve_bootmem" function instead of the
  NUMA aware "reserve_bootmem_generic".  I checked to make sure that no other
  function was using "reserve_bootmem" and found none, except the ones that
  had NUMA ifdef'ed out.

  I have tested this patch only on an ES7000 with NUMA on and off (numa=off)
  in a single (non-NUMA) and multi-cell (NUMA) configurations.
Signed-off-by: NAmul Shah <amul.shah@unisys.com>
  Looks-good-to: Vivek Goyal <vgoyal@in.ibm.com>
  Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The switch-back to reserve_bootmem() was accidentally introduced in
5c3391f9 when adding the BOOTMEM_EXCLUSIVE
parameter.
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch adds a 'flags' parameter to reserve_bootmem_generic() like it
already has been added in reserve_bootmem() with commit
72a7fe39.

It also changes all users to use BOOTMEM_DEFAULT, which doesn't effectively
change the behaviour. Since the change is x86-specific, I don't think it's
necessary to add a new API for migration. There are only 4 users of that
function.

The change is necessary for the next patch, using reserve_bootmem_generic()
for crashkernel reservation.
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix setup.c printk format warning:

linux-next-20080605/arch/x86/kernel/setup.c: In function 'setup_per_cpu_areas':
linux-next-20080605/arch/x86/kernel/setup.c:173: warning: format '%lu' expects type 'long unsigned int', but argument 2 has type 'ssize_t'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NVegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

  * Replace usages of MAX_NUMNODES with nr_node_ids in kernel/sched.c,
    where appropriate.  This saves some allocated space as well as many
    wasted cycles going through node entries that are non-existent.
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

sparse mutters:
arch/x86/mm/numa_64.c:195:27: warning: symbol 'end_pfn' shadows an earlier one
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

plat_node_bdata, cmdline, nodemap_addr, nodemap_size are local to
numa_64.c. Make them static
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Without this patch, my link fails with:

arch/x86/kernel/built-in.o(.cpuinit.text+0x3c6e): In function `get_local_pda':
: undefined reference to `_cpu_pda'
arch/x86/kernel/built-in.o(.cpuinit.text+0x3cd1): In function `get_local_pda':
: undefined reference to `after_bootmem'
arch/x86/kernel/built-in.o(.cpuinit.text+0x3cec): In function `get_local_pda':
: undefined reference to `_cpu_pda'
make[2]: *** [.tmp_vmlinux1] Error 1

Caused by commit 766da892634694f795b18b9538407816896fc470
    x86: remove static boot_cpu_pda array v2
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Ingo Molnar wrote:
...
> they crashed after about 3 randconfig iterations with:
>
>   early res: 4 [8000-afff] PGTABLE
>   early res: 5 [b000-b87f] MEMNODEMAP
> PANIC: early exception 0e rip 10:ffffffff8077a150 error 2 cr2 37
> Pid: 0, comm: swapper Not tainted 2.6.25-sched-devel.git-x86-latest.git #14
>
> Call Trace:
>  [<ffffffff81466196>] early_idt_handler+0x56/0x6a
>  [<ffffffff8077a150>] ? numa_set_node+0x30/0x60
>  [<ffffffff8077a129>] ? numa_set_node+0x9/0x60
>  [<ffffffff8147a543>] numa_init_array+0x93/0xf0
>  [<ffffffff8147b039>] acpi_scan_nodes+0x3b9/0x3f0
>  [<ffffffff8147a496>] numa_initmem_init+0x136/0x150
>  [<ffffffff8146da5f>] setup_arch+0x48f/0x700
>  [<ffffffff802566ea>] ? clockevents_register_notifier+0x3a/0x50
>  [<ffffffff81466a87>] start_kernel+0xd7/0x440
>  [<ffffffff81466422>] x86_64_start_kernel+0x222/0x280
...
Here's the fixup...  This one should follow the previous patches.

Thanks,
Mike
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

  * Remove the boot_cpu_pda array and pointer table from the data section.
    Allocate the pointer table and array during init.  do_boot_cpu()
    will reallocate the pda in node local memory and if the cpu is being
    brought up before the bootmem array is released (after_bootmem = 0),
    then it will free the initial pda.  This will happen for all cpus
    present at system startup.

    This removes 512k + 32k bytes from the data section.

For inclusion into sched-devel/latest tree.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

  * Consolidate node_to_cpumask operations and remove the 256k
    byte node_to_cpumask_map.  This is done by allocating the
    node_to_cpumask_map array after the number of possible nodes
    (nr_node_ids) is known.

  * Debug printouts when CONFIG_DEBUG_PER_CPU_MAPS is active have
    been increased.  It now shows faults when calling node_to_cpumask()
    and node_to_cpumask_ptr().

For inclusion into sched-devel/latest tree.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

  * Restore the nodenumber field in the x86_64 pda.  This field is slightly
    different than the x86_cpu_to_node_map mainly because it's a static
    indication of which node the cpu is on while the cpu to node map is a
    dyanamic mapping that may get reset if the cpu goes offline.  This also
    simplifies the numa_node_id() macro.

For inclusion into sched-devel/latest tree.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

  * Introduce a new PER_CPU macro called "EARLY_PER_CPU".  This is
    used by some per_cpu variables that are initialized and accessed
    before there are per_cpu areas allocated.

    ["Early" in respect to per_cpu variables is "earlier than the per_cpu
    areas have been setup".]

    This patchset adds these new macros:

	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)
	EXPORT_EARLY_PER_CPU_SYMBOL(_name)
	DECLARE_EARLY_PER_CPU(_type, _name)

	early_per_cpu_ptr(_name)
	early_per_cpu_map(_name, _idx)
	early_per_cpu(_name, _cpu)

    The DEFINE macro defines the per_cpu variable as well as the early
    map and pointer.  It also initializes the per_cpu variable and map
    elements to "_initvalue".  The early_* macros provide access to
    the initial map (usually setup during system init) and the early
    pointer.  This pointer is initialized to point to the early map
    but is then NULL'ed when the actual per_cpu areas are setup.  After
    that the per_cpu variable is the correct access to the variable.

    The early_per_cpu() macro is not very efficient but does show how to
    access the variable if you have a function that can be called both
    "early" and "late".  It tests the early ptr to be NULL, and if not
    then it's still valid.  Otherwise, the per_cpu variable is used
    instead:

	#define early_per_cpu(_name, _cpu) 			\
		(early_per_cpu_ptr(_name) ?			\
			early_per_cpu_ptr(_name)[_cpu] :	\
			per_cpu(_name, _cpu))

    A better method is to actually check the pointer manually.  In the
    case below, numa_set_node can be called both "early" and "late":

	void __cpuinit numa_set_node(int cpu, int node)
	{
	    int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);

	    if (cpu_to_node_map)
		    cpu_to_node_map[cpu] = node;
	    else
		    per_cpu(x86_cpu_to_node_map, cpu) = node;
	}

  * Add a flag "arch_provides_topology_pointers" that indicates pointers
    to topology cpumask_t maps are available.  Otherwise, use the function
    returning the cpumask_t value.  This is useful if cpumask_t set size
    is very large to avoid copying data on to/off of the stack.

  * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while
    the non-debug case has been optimized a bit.

  * Remove an unreferenced compiler warning in drivers/base/topology.c

  * Clean up #ifdef in setup.c

For inclusion into sched-devel/latest tree.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

  * Increase the limit of NR_CPUS to 4096 and introduce a boolean
    called "MAXSMP" which when set (e.g. "allyesconfig"), will set
    NR_CPUS = 4096 and NODES_SHIFT = 9 (512).

  * Changed max setting for NODES_SHIFT from 15 to 9 to accurately
    reflect the real limit.
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Mike Travis wrote:
> Ingo Molnar wrote:
>> * Mike Travis <travis@sgi.com> wrote:
>>
>>> [Ingo - please replace "PATCH 07/11" with this one.]

> >>>     *	Remove 544k bytes from the kernel by removing the boot_cpu_pda
> >>> 	array from the data section and allocating it during startup.

>>> 	Fixed panic in setup_per_cpu_areas when HOTPLUG_CPU not set.
>>>
>>> For inclusion into sched-devel/latest tree.
>> sched-devel.git randconfig testing found another crash with your queue:
>>
>> [    0.111060] Brought up 1 CPUs
>> [    0.111986] Total of 1 processors activated (4022.73 BogoMIPS).
>> [    0.112987] Testing NMI watchdog ... <1>BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
>> [    0.114982] IP: [<ffffffff8180d4a0>] check_nmi_watchdog+0xb0/0x210
>> [    0.114982] PGD 0
>> [    0.114982] Oops: 0000 [1] SMP
>> [    0.114982] CPU 0
>> [............]
>>
>>  http://redhat.com/~mingo/misc/config-Mon_Apr_28_23_25_25_CEST_2008.bad
>>  http://redhat.com/~mingo/misc/log-Mon_Apr_28_23_25_25_CEST_2008.bad
>>
>> 	Ingo
>
> Hi Ingo,
>
> I need a bit more information on your hardware configuration.  Building a
> kernel with the above config file started up fine on both the Intel and AMD
> boxes.
>
> Based on the above output it looks like it might be a UP machine?
...

Ok, I think I found it.  In check_nmi_watchdog():

        for (cpu = 0; cpu < NR_CPUS; cpu++)
                prev_nmi_count[cpu] = cpu_pda(cpu)->__nmi_count;

As I mentioned it works fine on both of my systems so could you try it out?

Thanks!
Mike
--

  * Change function check_nmi_watchdog() to use nr_cpu_ids instead of NR_CPUS.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
Signed-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

also make bus_numa work even if ACPI_NUMA is not defined.

don't call pxm_to_node again, and use node directly.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

a numa system (with multi HT chains) may return node without ram. Aka it
is not online. Try to get an online node, otherwise return -1.
Signed-off-by: NYinghai Lu <yinghai.lu@sun.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Conflicts:

	arch/x86/Kconfig
	arch/x86/kernel/io_apic_32.c
	arch/x86/kernel/setup_64.c
	arch/x86/mm/init_32.c
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Some HP laptops have a problem with their DSDT reporting as
HP/SB400/10000, which includes some code which overrides all temperature
trip points to 16C if the INTIN2 input of the I/O APIC is enabled.  This
input is incorrectly designated the ISA IRQ 0 via an interrupt source
override even though it is wired to the output of the master 8259A and
INTIN0 is not connected at all.  So far two models have been identified,
namely nx6125 and nx6325.

Use a knob provided by the I/O APIC interrupt registration code to
abandon any attempts to route IRQ 0 through the I/O APIC for these
systems.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

As discovered recently some systems exhibit problems when the 8254 timer
IRQ is routed through the I/O APIC.  These problems do not affect the
timer IRQ itself and therefore cannot be detected when the correctness of
operation of the interrupt is verified in check_timer().  Therefore the
I/O APIC path of the timer IRQ has to be disabled entirely.

This is a change that lets platforms ask for the timer IRQ not to be
registered in the I/O APIC interrupt tables.  The local APIC and ExtINTA
paths are unaffected.  This request is only taken into account for ACPI
platforms as MP table systems seem unaffected so far.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

"Maciej W. Rozycki" <macro@linux-mips.org> said:

> Given X86_64 selects X86_LOCAL_APIC I am not sure the redundancy seen
>above does not actually obscure the logic behind...  I think:
>
>       depends on X86_LOCAL_APIC && !X86_VISWS
>
>would be clearer and get the same.
Suggested-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>