Add a smp_ops interface.  This abstracts the API defined by
<linux/smp.h> for use within arch/i386.  The primary intent is that it
be used by a paravirtualizing hypervisor to implement SMP, but it
could also be used by non-APIC-using sub-architectures.

This is related to CONFIG_PARAVIRT, but is implemented unconditionally
since it is simpler that way and not a highly performance-sensitive
interface.
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>

Now we have an explicit per-cpu GDT variable, we don't need to keep the
descriptors around to use them to find the GDT: expose cpu_gdt directly.

We could go further and make load_gdt() pack the descriptor for us, or even
assume it means "load the current cpu's GDT" which is what it always does.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Fix "Section mismatch" warnings in arch/x86_64/kernel/time.c
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Signed-off-by: NAndi Kleen <ak@suse.de>

commit 5e518d76 did the same change to
i386's variant.

With this change, i386's and x86-64's versions are identical, raising
the question whether the x86-64 one should go (just like there's only
one instance of edd.S).
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch touches the NMI watchdog every MAX_ORDER_NR_PAGES
to inhibit the machine from triggering an NMI while the CPUs
are locked. This situation is happening on boxes with more
than 64CPUs and 128GB of RAM when Alt-SysRq-m is performed.

It has been succesfully tested for regression on uni, 2, 4, 8
32, and 64 CPU boxes with various memory configuration.
Signed-off-by: NAndi Kleen <ak@suse.de>

Current vsyscall_gtod_data is large (3 or 4 cache lines dirtied at timer
interrupt). We can shrink it to exactly 64 bytes (1 cache line on AMD64)

Instead of copying a whole struct clocksource, we copy only needed fields.

I deleted an unused field : offset_base

This patch fixes one oddity in vgettimeofday(): It can returns a timeval with
tv_usec = 1000000. Maybe not a bug, but why not doing the right thing ?
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

There is a tiny probability that the return value from vtime(time_t *t) is
Signed-off-by: NAndi Kleen <ak@suse.de>

different than the value stored in *t

Using a temporary variable solves the problem and gives a faster code.

   17:   48 85 ff                test   %rdi,%rdi
   1a:   48 8b 05 00 00 00 00    mov    0(%rip),%rax        #
__vsyscall_gtod_data.wall_time_tv.tv_sec
   21:   74 03                   je     26
   23:   48 89 07                mov    %rax,(%rdi)
   26:   c9                      leaveq
   27:   c3                      retq
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>

Many years ago, UNEXPECTED_IO_APIC() contained printk()'s (but nothing more).

Now that it's completely empty for years, we can as well remove it.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndi Kleen <ak@suse.de>

- there's no reason for duplicating the prototype from
  include/linux/syscalls.h in include/asm-x86_64/unistd.h
- every file should #include the headers containing the prototypes for
  it's global functions
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndi Kleen <ak@suse.de>

x86_64 currently simulates a list using the index and private fields of the
page struct.  Seems that the code was inherited from i386.  But x86_64 does
not use the slab to allocate pgds and pmds etc.  So the lru field is not
used by the slab and therefore available.

This patch uses standard list operations on page->lru to realize pgd
tracking.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Signed-off-by: NParag Warudkar <parag.warudkar@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

suggested by Jan Beulich
Signed-off-by: NAndi Kleen <ak@suse.de>

Move X86_EFLAGS_IF et al out to a new header: processor-flags.h, so we
can include it from irqflags.h and use it in raw_irqs_disabled_flags().

As a side-effect, we could now use these flags in .S files.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NParag Warudkar <parag.warudkar@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

On x86-64, kernel memory freed after init can be entirely unmapped instead
of just getting 'poisoned' by overwriting with a debug pattern.

On i386 and x86-64 (under CONFIG_DEBUG_RODATA), kernel text and bug table
can also be write-protected.

Compared to the first version, this one prevents re-creating deleted
mappings in the kernel image range on x86-64, if those got removed
previously. This, together with the original changes, prevents temporarily
having inconsistent mappings when cacheability attributes are being
changed on such pages (e.g. from AGP code). While on i386 such duplicate
mappings don't exist, the same change is done there, too, both for
consistency and because checking pte_present() before using various other
pte_XXX functions is a requirement anyway. At once, i386 code gets
adjusted to use pte_huge() instead of open coding this.

AK: split out cpa() changes
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Fix various broken corner cases in i386 and x86-64 change_page_attr.

AK: split off from tighten kernel image access rights
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

paravirt.c used to implement native versions of all low-level
functions.  Far cleaner is to have the native versions exposed in the
headers and as inline native_XXX, and if !CONFIG_PARAVIRT, then simply
#define XXX native_XXX.

There are several nice side effects:

1) write_dt_entry() now takes the correct "struct Xgt_desc_struct *"
   not "void *".

2) load_TLS is reintroduced to the for loop, not manually unrolled
   with a #error in case the bounds ever change.

3) Macros become inlines, with type checking.

4) Access to the native versions is trivial for KVM, lguest, Xen and
   others who might want it.
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@muc.de>
Cc: Avi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Rename boot_gdt_table to boot_gdt to avoid the duplicate T(able).
Signed-off-by: NSebastien Dugue <sebastien.dugue@bull.net>
Signed-off-by: NAndi Kleen <ak@suse.de>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

We now have cpu_init() and secondary_cpu_init() doing nothing but calling
_cpu_init() with the same arguments.  Rename _cpu_init() to cpu_init() and use
it as a replcement for secondary_cpu_init().
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Now we are no longer dynamically allocating the GDT, we don't need the
"cpu_gdt_table" at all: we can switch straight from "boot_gdt_table" to the
per-cpu GDT.  This means initializing the cpu_gdt array in C.

The boot CPU uses the per-cpu var directly, then in smp_prepare_cpus() it
switches to the per-cpu copy just allocated.  For secondary CPUs, the
early_gdt_descr is set to point directly to their per-cpu copy.

For UP the code is very simple: it keeps using the "per-cpu" GDT as per SMP,
but we never have to move.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Allocating PDA and GDT at boot is a pain.  Using simple per-cpu variables adds
happiness (although we need the GDT page-aligned for Xen, which we do in a
followup patch).

[akpm@linux-foundation.org: build fix]
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Because the command line is increased to 2048 characters after 2.6.21, it's
not possible for boot loaders and userspace tools to determine the length
of the command line the kernel can understand.  The benefit of knowing the
length is that users can be warned if the command line size is too long
which prevents surprise if things don't work after bootup.

This patch updates the boot protocol to contain a field called
"cmdline_size" that contain the length of the command line (excluding the
terminating zero).

The patch also adds missing fields (of protocol version 2.05) to the x86_64
setup code.
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Alon Bar-Lev <alon.barlev@gmail.com>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

The specific case I am encountering is kdump under Xen with a 64 bit
hypervisor and 32 bit kernel/userspace.  The dump created is 64 bit due to
the hypervisor but the dump kernel is 32 bit for maximum compatibility.

It's possibly less likely to be useful in a purely native scenario but I
see no reason to disallow it.

[akpm@linux-foundation.org: build fix]
Signed-off-by: NIan Campbell <ian.campbell@xensource.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Acked-by: NVivek Goyal <vgoyal@in.ibm.com>
Cc: Horms <horms@verge.net.au>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

GCC (4.1 at least) unrolls it anyway, but I can't believe this code
was ever justifiable.  (I've also submitted a patch which cleans up
i386, which is even uglier).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Whenever we schedule, __switch_to calls load_esp0 which does:

	tss->esp0 = thread->esp0;

This is never initialized for the initial thread (ie "swapper"), so when we're
scheduling that, we end up setting esp0 to 0.  This is fine: the swapper never
leaves ring 0, so this field is never used.

lguest, however, gets upset that we're trying to used an unmapped page as our
kernel stack.  Rather than work around it there, let's initialize it.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

The lguest patches somehow managed to trigger this:

In file included from arch/i386/lguest/lguest.c:38:
include/asm/asm-offsets.h:67:1: warning: "VDSO_PRELINK" redefined
In file included from include/linux/elf.h:7,
                 from include/linux/module.h:15,
                 from include/linux/device.h:21,
                 from include/linux/interrupt.h:15,
                 from arch/i386/lguest/lguest.c:27:
include/asm/elf.h:140:1: warning: this is the location of the previous definition

I assume that using the same identifier twice was a bad idea..

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

Create a document to explain how to use numa=fake in conjunction with cpusets
for coarse memory resource management.

An attempt to get more awareness and testing for this feature.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

remove the reporting of the constant_tsc flag from the "power management"
field in /proc/cpuinfo.  The NULL value there was replaced by "" because
the former would result in a printout of [8] if the flag is set.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

Extends the numa=fake x86_64 command-line option to split the remaining system
memory into nodes of fixed size.  Any leftover memory is allocated to a final
node unless the command-line ends with a comma.

For example:
  numa=fake=2*512,*128	gives two 512M nodes and the remaining system
			memory is split into nodes of 128M each.

This is beneficial for systems where the exact size of RAM is unknown or not
necessarily relevant, but the size of the remaining nodes to be allocated is
known based on their capacity for resource management.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Extends the numa=fake x86_64 command-line option to split the remaining
system memory into equal-sized nodes.

For example:
numa=fake=2*512,4*	gives two 512M nodes and the remaining system
			memory is split into four approximately equal
			chunks.

This is beneficial for systems where the exact size of RAM is unknown or not
necessarily relevant, but the granularity with which nodes shall be allocated
is known.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Extends the numa=fake x86_64 command-line option to allow for configurable
node sizes.  These nodes can be used in conjunction with cpusets for coarse
memory resource management.

The old command-line option is still supported:
  numa=fake=32	gives 32 fake NUMA nodes, ignoring the NUMA setup of the
		actual machine.

But now you may configure your system for the node sizes of your choice:
  numa=fake=2*512,1024,2*256
		gives two 512M nodes, one 1024M node, two 256M nodes, and
		the rest of system memory to a sixth node.

The existing hash function is maintained to support the various node sizes
that are possible with this implementation.

Each node of the same size receives roughly the same amount of available
pages, regardless of any reserved memory with its address range.  The total
available pages on the system is calculated and divided by the number of equal
nodes to allocate.  These nodes are then dynamically allocated and their
borders extended until such time as their number of available pages reaches
the required size.

Configurable node sizes are recommended when used in conjunction with cpusets
for memory control because it eliminates the overhead associated with scanning
the zonelists of many smaller full nodes on page_alloc().

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Fix comments to represent the true number of quadwords in GDT.
Signed-off-by: NAhmed S. Darwish <darwish.07@gmail.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

This patch makes the needlessly global vmi_pmd_clear() static.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndi Kleen <ak@suse.de>
Acked-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

Reorder code to avoid multiple inclusion of elf.h.

#undef several symbols to avoid build errors over redefinitions.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Change mark_tsc_unstable() so it takes a string argument, which holds the
reason the TSC was marked unstable.

This is then displayed the first time mark_tsc_unstable is called.

This should help us better debug why the TSC was marked unstable on certain
systems and allow us to make sure we're not being overly paranoid when
throwing out this troublesome clocksource.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

Work around a warning with -Wmissing-prototypes in
arch/i386/kernel/asm-offsets.c

The warning isn't gcc's fault - asm-offsets.c is simply a special file.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

clean up unneeded type cast by properly declare data type.
Signed-off-by: NKen Chen <kenchen@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>

Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>