i386 and x86_64 used two different schemes for maintaining the gdt.
With this patch, x86_64 initial gdt table is defined in a .c file,
same way as i386 is now. Also, we call it "gdt_page", and the descriptor,
"early_gdt_descr". This way we achieve common naming, which can allow for
more code integration.
Signed-off-by: NGlauber Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

call x86_64's init_rsp stack_start, just as i386 does.
Put a zeroed stack segment for consistency. With this,
we can eliminate one ugly ifdef in smpboot.c.
Signed-off-by: NGlauber Costa <gcosta@redhat.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>

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>

  * 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>

  * 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>

 If configured to use the I/O APIC, the NMI watchdog is deemed to fail if
the chip has been deactivated as a result of "nosmp".  Downgrade to the
local APIC watchdog similarly to what is done for the UP case.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This reverts commit 791b93d3dfaf16c23e978bec0cc0a3dd9d855d63.

A better fix from Maciej will be merged.

If configured to use the I/O APIC, the NMI watchdog is deemed to fail if
the chip has been deactivated as a result of "nosmp".  Downgrade to the
local APIC watchdog similarly to what is done for the UP case.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The local APIC is no longer forced off when "nosmp" has been specified.
Correct the message printed.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Vegard Nossum reported crashes during cpu hotplug tests:

  http://marc.info/?l=linux-kernel&m=121413950227884&w=4

In function _cpu_up, the panic happens when calling
__raw_notifier_call_chain at the second time. Kernel doesn't panic when
calling it at the first time. If just say because of nr_cpu_ids, that's
not right.

By checking the source code, I found that function do_boot_cpu is the culprit.
Consider below call chain:
 _cpu_up=>__cpu_up=>smp_ops.cpu_up=>native_cpu_up=>do_boot_cpu.

So do_boot_cpu is called in the end. In do_boot_cpu, if
boot_error==true, cpu_clear(cpu, cpu_possible_map) is executed. So later
on, when _cpu_up calls __raw_notifier_call_chain at the second time to
report CPU_UP_CANCELED, because this cpu is already cleared from
cpu_possible_map, get_cpu_sysdev returns NULL.

Many resources are related to cpu_possible_map, so it's better not to
change it.

Below patch against 2.6.26-rc7 fixes it by removing the bit clearing in
cpu_possible_map.
Signed-off-by: NZhang Yanmin <yanmin_zhang@linux.intel.com>
Tested-by: NVegard Nossum <vegard.nossum@gmail.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Priit Laes reported the following warning:

Call Trace:
 [<ffffffff8022f1e1>] warn_on_slowpath+0x51/0x63
 [<ffffffff80282e48>] sys_ioctl+0x2d/0x5d
 [<ffffffff805185ff>] _spin_lock+0xe/0x24
 [<ffffffff80227459>] task_rq_lock+0x3d/0x73
 [<ffffffff805133c3>] set_cpu_sibling_map+0x336/0x350
 [<ffffffff8021c1b8>] read_apic_id+0x30/0x62
 [<ffffffff806d921d>] verify_local_APIC+0x90/0x138
 [<ffffffff806d84b5>] native_smp_prepare_cpus+0x1f9/0x305
 [<ffffffff806ce7b1>] kernel_init+0x59/0x2d9
 [<ffffffff80518a26>] _spin_unlock_irq+0x11/0x2b
 [<ffffffff8020bf48>] child_rip+0xa/0x12
 [<ffffffff806ce758>] kernel_init+0x0/0x2d9
 [<ffffffff8020bf3e>] child_rip+0x0/0x12

fix this by generally disabling preemption in native_smp_prepare_cpus().
Reported-and-bisected-by: NPriit Laes <plaes@plaes.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

move early_res related from e820_64.c to e820.c
make edba detection to be done in head32.c
remove smp_alloc_memory, because we have fixed trampoline address now.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>

 arch/x86/kernel/e820.c              |  214 ++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/e820_64.c           |  196 --------------------------------
 arch/x86/kernel/head32.c            |   76 ++++++++++++
 arch/x86/kernel/setup_32.c          |  109 +++---------------
 arch/x86/kernel/smpboot.c           |   17 --
 arch/x86/kernel/trampoline.c        |    2
 arch/x86/mach-voyager/voyager_smp.c |    9 -
 include/asm-x86/e820.h              |    6 +
 include/asm-x86/e820_64.h           |    9 -
 include/asm-x86/smp.h               |    1
 arch/x86/kernel/e820.c              |  214 ++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/e820_64.c           |  196 --------------------------------
 arch/x86/kernel/head32.c            |   76 ++++++++++++
 arch/x86/kernel/setup_32.c          |  109 +++---------------
 arch/x86/kernel/smpboot.c           |   17 --
 arch/x86/kernel/trampoline.c        |    2
 arch/x86/mach-voyager/voyager_smp.c |    9 -
 include/asm-x86/e820.h              |    6 +
 include/asm-x86/e820_64.h           |    9 -
 include/asm-x86/smp.h               |    1
 arch/x86/kernel/e820.c              |  214 ++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/e820_64.c           |  196 --------------------------------
 arch/x86/kernel/head32.c            |   76 ++++++++++++
 arch/x86/kernel/setup_32.c          |  109 +++---------------
 arch/x86/kernel/smpboot.c           |   17 --
 arch/x86/kernel/trampoline.c        |    2
 arch/x86/mach-voyager/voyager_smp.c |    9 -
 include/asm-x86/e820.h              |    6 +
 include/asm-x86/e820_64.h           |    9 -
 include/asm-x86/smp.h               |    1
 10 files changed, 320 insertions(+), 319 deletions(-)
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Removed duplicated include <asm/nmi.h> in
arch/x86/kernel/smpboot.c.
Signed-off-by: NHuang Weiyi <weiyi.huang@gmail.com>
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

After resume on a 2cpu laptop, kernel builds collapse with a sed hang,
sh or make segfault (often on 20295564), real-time signal to cc1 etc.

Several hurdles to jump, but a manually-assisted bisect led to -rc1's
d2bcbad5 x86: do not zap_low_mappings
in __smp_prepare_cpus.  Though the low mappings were removed at bootup,
they were left behind (with Global flags helping to keep them in TLB)
after resume or cpu online, causing the crashes seen.

Reinstate zap_low_mappings (with local __flush_tlb_all) for each cpu_up
on x86_32.  This used to be serialized by smp_commenced_mask: that's now
gone, but a low_mappings flag will do.  No need for native_smp_cpus_done
to repeat the zap: let mem_init zap BSP's low mappings just like on UP.

(In passing, fix error code from native_cpu_up: do_boot_cpu returns a
variety of diagnostic values, Dprintk what it says but convert to -EIO.
And save_pg_dir separately before zap_low_mappings: doesn't matter now,
but zapping twice in succession wiped out resume's swsusp_pg_dir.)

That worked well on the duo and one quad, but wouldn't boot 3rd or 4th
cpu on P4 Xeon, oopsing just after unlock_ipi_call_lock.  The TLB flush
IPI now being sent reveals a long-standing bug: the booting cpu has its
APIC readied in smp_callin at the top of start_secondary, but isn't put
into the cpu_online_map until just before that unlock_ipi_call_lock.

So native_smp_call_function_mask to online cpus would send_IPI_allbutself,
including the cpu just coming up, though it has been excluded from the
count to wait for: by the time it handles the IPI, the call data on
native_smp_call_function_mask's stack may well have been overwritten.

So fall back to send_IPI_mask while cpu_online_map does not match
cpu_callout_map: perhaps there's a better APICological fix to be
made at the start_secondary end, but I wouldn't know that.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch makes the needlessly global additional_cpus static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

start_secondary() needlessly became global.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

set up sane APIC state even in the nosmp case.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

cpu_online(), cpu_present(), for_each_possible_cpu(), num_possible_cpus()
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Make KERNEL_PGD_PTRS common, as previously it was only being defined
for 32-bit.

There are a couple of follow-on changes from this:
 - KERNEL_PGD_PTRS was being defined in terms of USER_PGD_PTRS.  The
   definition of USER_PGD_PTRS doesn't really make much sense on x86-64,
   since it can have two different user address-space configurations.
   I renamed USER_PGD_PTRS to KERNEL_PGD_BOUNDARY, which is meaningful
   for all of 32/32, 32/64 and 64/64 process configurations.

 - USER_PTRS_PER_PGD was also defined and was being used for similar
   purposes.  Converting its users to KERNEL_PGD_BOUNDARY left it
   completely unused, and so I removed it.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Zach Amsden <zach@vmware.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

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

This patch changes smpboot.c so that it can start slave cpus running
in UV non-unique apicid mode. The SIPI must be sent using a UV-specific
mechanism.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

move the trampoline setup code out of smpboot.c - UP kernels can have
suspend support too.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Move wakeup code to .c, so that video mode setting code can be shared
between boot and wakeup. Remove nasty assembly code in 64-bit case by
re-using trampoline code. Stack setup was fixed to clear high 16bits
of %esp, maybe that fixes some machines.

.c code sharing and morse code was done H. Peter Anvin, Sam Ravnborg
reviewed kbuild related stuff, and it seems okay to him. Rafael did
some cleanups.

[rjw:
* Made the patch stop breaking compilation on x86-32
* Added arch/x86/kernel/acpi/sleep.h
* Got rid of compiler warnings in arch/x86/kernel/acpi/sleep.c
* Fixed 32-bit compilation on x86-64 systems
* Added include/asm-x86/trampoline.h and fixed the non-SMP
  compilation on 64-bit x86
* Removed arch/x86/kernel/acpi/sleep_32.c which was not used
* Fixed some breakage caused by the integration of smpboot.c done
  under us in the meantime]
Signed-off-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Reviewed-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch fixes mismatch warnings in smp_checks() (in arch/x86/kernel/smpboot.c):

WARNING: arch/x86/kernel/built-in.o(.text+0x11922): Section mismatch in reference from the function smp_checks()
to the variable .cpuinit.data:smp_b_stepping
The function smp_checks() references
the variable __cpuinitdata smp_b_stepping.
This is often because smp_checks lacks a __cpuinitdata
annotation or the annotation of smp_b_stepping is wrong.
Signed-off-by: NJacek Luczak <luczak.jacek@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

> > Make sure that we clear the "shutdown status flag" in the CMOS
> > register after each CPU is brought up.  This fixes a problem where the
> > "shutdown status flag" may remain set when a CPU is brought up after
> > booting.
>
> btw., what problem does this result in, exactly?

The shutdown status flag set to "0xA", corresponds to "JMP double word
request without INT init".

This JMP at reboot time is at an unintended location. And results in
Triple faults in our case.
Though this error at reboot can be safely ignored in a VM environment,
am not sure what the effect would be on a physical system. May be it
will result in a triple fault and an eventual hardware reset thus
masking this BUG in the kernel.

This fix just makes sure that we reset that status flag after
initialization is done.

Fix paranoia about using BIOS quickboot mechanism.

Make sure that we clear the "shutdown status flag" in the CMOS register
after each CPU is brought up.  This fixes a problem where the "shutdown
status flag" may remain set when a CPU is brought up after booting.
Signed-off-by: NAlok N Kataria <akataria@vmware.com>
Signed-off-by: NDan Arai <arai@vmware.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

UV supports really big systems. So big, in fact, that the APICID register
does not contain enough bits to contain an APICID that is unique across all
cpus.

The UV BIOS supports 3 APICID modes:

	- legacy mode. This mode uses the old APIC mode where
	  APICID is in bits [31:24] of the APICID register.

	- x2apic mode. This mode is whitebox-compatible. APICIDs
	  are unique across all cpus. Standard x2apic APIC operations
	  (Intel-defined) can be used for IPIs. The node identifier
	  fits within the Intel-defined portion of the APICID register.

	- x2apic-uv mode. In this mode, the APICIDs on each node have
	  unique IDs, but IDs on different node are not unique. For example,
	  if each mode has 32 cpus, the APICIDs on each node might be
	  0 - 31. Every node has the same set of IDs.
	  The UV hub is used to route IPIs/interrupts to the correct node.
	  Traditional APIC operations WILL NOT WORK.

In x2apic-uv mode, the ACPI tables all contain a full unique ID (note:
exact bit layout still changing but the following is close):

	nnnnnnnnnnlc0cch
		n = unique node number
		l = socket number on board
		c = core
		h = hyperthread

Only the "lc0cch" bits are written to the APICID register. The remaining bits are
supplied by having the get_apic_id() function "OR" the extra bits into the value
read from the APICID register. (Hmmm.. why not keep the ENTIRE APICID register
in per-cpu data....)

The x2apic-uv mode is recognized by the MADT table containing:
	  oem_id = "SGI"
	  oem_table_id = "UV-X"
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Introduce a function to read the local APIC_ID.

This change is in preparation for additional changes to
the APICID functions that will come in a later patch.
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NAlexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>