A patch by Eric was merged (f2b36db6)
and later on reverted back (1e4c85f9).

Along with above patch, another patch was posted and has been merged
(3d1675b4).  That patch was dependent on
the above patch and now it should also be reverted.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix up booting with sparse mem enabled. Otherwise it would just
cause an early PANIC at boot.
Signed-off-by: NBob Picco <bob.picco@hp.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is needed for large multinode IBM systems which have a sparse
APIC space in clustered mode, fully covering the available 8 bits.

The previous kernels would limit the local APIC number to 127,
which caused it to reject some of the CPUs at boot.

I increased the maximum and shrunk the apic_version array a bit
to make up for that (the version is only 8 bit, so don't need
an full int to store)

Cc:  Chris McDermott <lcm@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

CONFIG_CHECKING covered some debugging code used in the early times
of the port. But it wasn't even SMP safe for quite some time
and the bugs it checked for seem to be gone.

This patch removes all the code to verify GS at kernel entry. There
haven't been any new bugs in this area for a long time.

Previously it also covered the sysctl for the page fault tracing.
That didn't make much sense because that code was unconditionally
compiled in. I made that a boot option now because it is typically
only useful at boot.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The current x86_64 NUMA memory code is inconsequent when it comes to node
memory ranges. The exact behaviour varies depending on which config option
that is used.

setup_node_bootmem() has start and end as arguments and these are used to
calculate the size of the node like this: (end - start). This is all fine
if end is pointing to the first non-available byte. The problem is that the
current x86_64 code sometimes treats it as the last present byte and sometimes
as the first non-available byte. The result is that some configurations might
lose a page at the end of the range.

This patch tries to fix CONFIG_ACPI_NUMA, CONFIG_K8_NUMA and CONFIG_NUMA_EMU
so they all treat the end variable as the first non-available byte. This is
the same way as the single node code.

The patch is boot tested on dual x86_64 hardware with the above configurations,
but maybe the removed code is needed as some workaround?
Signed-off-by: NMagnus Damm <magnus@valinux.co.jp>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The logging for boot errors was turned off because it was broken
on some AMD systems. But give Intel EM64T systems a chance because they are
supposed to be correct there.

The advantage is that there is a chance to actually log uncorrected
machine checks after the reset.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

On x86_64 arches, there is no way to choose ACPI_NUMA without having to choose
K8_NUMA.  CONFIG_K8_NUMA is not needed for Intel EM64T NUMA boxes.  It also
looks odd if you have to select ACPI_NUMA from the power management menu.
This patch fixes those oddities.  Patch does the following:

1. Makes NUMA a config option like other arches
2. Makes topology detection options like K8_NUMA dependent on NUMA
3. Choosing ACPI NUMA detection can be done from the standard
   "Processor type and features" menu

AK: I fixed up the dependencies and changed the help texts a bit
on top of Kiran's patch.
Signed-off-by: NRavikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: NShai Fultheim <shai@scalex86.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Keeping this function does not makes sense because it's a copied (and
buggy) copy of sys_time.  The only difference is that now.tv_sec (which is
a time_t, i.e.  a 64-bit long) is copied (and truncated) into a int
(32-bit).

The prototype is the same (they both take a long __user *), so let's drop
this and redirect it to sys_time (and make sure it exists by defining
__ARCH_WANT_SYS_TIME).

Only disadvantage is that the sys_stime definition is also compiled (may be
fixed if needed by adding a separate __ARCH_WANT_SYS_STIME macro, and
defining it for all arch's defining __ARCH_WANT_SYS_TIME except x86_64).
Acked-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The current value was correct before the introduction of Intel EM64T support -
but now L1_CACHE_SHIFT_MAX can be less than L1_CACHE_SHIFT, which _is_ funny!

Between the few users of ____cacheline_maxaligned_in_smp, we also have (for
example) rcu_ctrlblk, and struct zone, with zone->{lru_,}lock.  I.e.  we have
a lot of excess cacheline bouncing on them.

No correctness issues, obviously.  So this could even be merged for 2.6.14
(I'm not a fan of this idea, though).

CC: Andi Kleen <ak@suse.de>
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Not needed since x86-64 always uses the spinlock based rwsems.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

B stepping were the first shipping Opterons. memcpy/memset/copy_page/
clear_page had special optimized version for them. These are really
old and in the minority now and the difference to the generic versions
(using rep microcode) is not that big anyways. So just remove them.

TODO: figure out optimized versions for Intel Netburst based EM64T
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Old code could retry for 10 seconds worst time. Only try it
for one second now.

Suggested by Yinghai Lu

Cc: Yinghai.Lu@amd.com
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix the Intel cache detection code assumption that number of threads
sharing the cache will either be equal to number of HT or core siblings.

This also cleans up the code in general a bit.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fields obtained through cpuid vector 0x1(ebx[16:23]) and
vector 0x4(eax[14:25], eax[26:31]) indicate the maximum values and might not
always be the same as what is available and what OS sees.  So make sure
"siblings" and "cpu cores" values in /proc/cpuinfo reflect the values as seen
by OS instead of what cpuid instruction says. This will also fix the buggy BIOS
cases (for example where cpuid on a single core cpu says there are "2" siblings,
even when HT is disabled in the BIOS.
http://bugzilla.kernel.org/show_bug.cgi?id=4359)
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When they were disabled before (e.g. after a panic) it's better
to keep them off, otherwise followon panics can happen from timer
interrupt handlers etc.

Drawback is that pageup in the console won't work anymore though.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

No functional changes.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

They report 40bit, but only have 36bits of physical address space.
This caused problems with setting up the correct masks for MTRR.

CPUID workaround for steppings 0F33h(supporting x86) and 0F34h(supporting x86
and EM64T). Detail info can be found at:
http://download.intel.com/design/Xeon/specupdt/30240216.pdf
http://download.intel.com/design/Pentium4/specupdt/30235221.pdf

Signed-off-by: Shaohua Li<shaohua.li@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Ugh!

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

So far all new ones have worked and there isn't much variation because
the CPU does all the interesting bits.

So enable try unsupported by default.

Can be still disabled with try_unsupported=0 (module) or
amd64.try_unsupported=0   (boot option)
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

(no name because I'm not sure of the correct name)

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

Compute the highest possible value for memnode_shift, in order to reduce
footprint of memnodemap[] to the minimum, thus making all users
(phys_to_nid(), kfree()), more cache friendly.

Before the patch :

 Node 0 MemBase 0000000000000000 Limit 00000001ffffffff
 Node 1 MemBase 0000000200000000 Limit 00000003ffffffff
 Using 23 for the hash shift. Max adder is 3ffffffff

After the patch :

 Node 0 MemBase 0000000000000000 Limit 00000001ffffffff
 Node 1 MemBase 0000000200000000 Limit 00000003ffffffff
 Using 33 for the hash shift.

In this case, only 2 bytes of memnodemap[] are used, instead of 2048
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This allows to run 64bit signal handlers in 64bit processes that run small
code snippets in compat mode.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

With a NR_CPUS==128 kernel with CPU hotplug enabled we would waste 4MB
on per CPU data of all possible CPUs.  The reason was that HOTPLUG
always set up possible map to NR_CPUS cpus and then we need to allocate
that much (each per CPU data is roughly ~32k now)

The underlying problem is that ACPI didn't tell us how many hotplug CPUs
the platform supports.  So the old code just assumed all, which would
lead to this memory wastage.

This implements some new heuristics:

 - If the BIOS specified disabled CPUs in the ACPI/mptables assume they
   can be enabled later (this is bending the ACPI specification a bit,
   but seems like a obvious extension)
 - The user can overwrite it with a new additionals_cpus=NUM option
 - Otherwise use half of the available CPUs or 2, whatever is more.

Cc: ashok.raj@intel.com
Cc: len.brown@intel.com
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Pointed out by Eric Dumazet
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I got some questions on this, so just fix up the documentation.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Minor victory on the continuous quest against all stray extern.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Minor cleanup - remove obsolete extern
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Adding __initdata_* to asm-generic/sections.h
Replaces a lot of open coded externs in arch/x86_64/*
I had to change __bss_end to __bss_stop to match the other architectures.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It is for physical addresses, not for PFNs.

Pointed out by Tejun Heo.

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

We should zap the low mappings, as soon as possible, so that we can catch
kernel bugs more effectively. Previously early boot had NULL mapped
and didn't trap on NULL references.

This patch introduces boot_level4_pgt, which will always have low identity
addresses mapped.  Druing boot, all the processors will use this as their
level4 pgt.  On BP, we will switch to init_level4_pgt as soon as we enter C
code and zap the low mappings as soon as we are done with the usage of
identity low mapped addresses.  On AP's we will zap the low mappings as
soon as we jump to C code.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Not go from the CPU number to an mapping array.
Mode number is often used now in fast paths.

This also adds a generic numa_node_id to all the topology includes

Suggested by Eric Dumazet
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix

  arch/x86_64/kernel/aperture.c: In function #iommu_hole_init#:
  arch/x86_64/kernel/aperture.c:199: warning: #aper_order# may be used uninitialized in this function
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

According to cpuid instruction in IA32 SDM-Vol2, when computing cpu model,
we need to consider extended model ID for family 0x6 also.

AK: Also added fixes/simplifcation from Petr Vandrovec
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove duplicate __cpuinit in smp.c. Already defined in init.h which is
already included.
Signed-off-by: NAshok Raj <ashok.raj@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Has been introduced for x86-64 at some point to save memory
in struct page, but has been obsolete for some time. Just
remove it.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

pfn_to_page really requires pfn_valid to be true now, no question.
Some people stumbled over it, but it was misleading and wrong.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>