the exact timing of the corruption check isn't too important (it's once a
minute timer), use round_jiffies() to align it and avoid extra wakeups.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This bugzilla:

  http://bugzilla.kernel.org/show_bug.cgi?id=11237

Documents a wide range of systems where the BIOS utilizes the first
64K of physical memory during suspend/resume and other hardware events.

Currently we reserve this memory on all AMI and Phoenix BIOS systems.
Life is too short to hunt subtle memory corruption problems like this,
so we try to be robust by default.

Still, allow this to be overriden: allow users who want that first 64K
of memory to be available to the kernel disable the quirk, via
CONFIG_X86_RESERVE_LOW_64K=n.

Also, allow the early reservation to overlap with other
early reservations.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

there's multiple reports about suspend/resume related low memory
corruption in this bugzilla:

  http://bugzilla.kernel.org/show_bug.cgi?id=11237

the common pattern is that the corruption is caused by the BIOS,
and that it affects some portion of the first 64K of physical RAM.

So add a DMI quirk

This will waste 64K RAM on 'good' systems too, but without knowing
the exact nature of this BIOS memory corruption this is the safest
approach.

This might as well solve a wide range of suspend/resume breakages
under Linux.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Alan Jenkins and Andy Wettstein reported a suspend/resume memory
corruption bug and extensively documented it here:

   http://bugzilla.kernel.org/show_bug.cgi?id=11237

The bug is that the BIOS overwrites 1K of memory at 0xc000 physical,
without registering it in e820 as reserved or giving the kernel any
idea about this.

Detect AMI BIOSen and reserve that 1K.

We paint this bug around with a very broad brush (reserving that 1K on all
AMI BIOS systems), as the bug was extremely hard to find and needed several
weeks and lots of debugging and patching.

The bug was found via the CONFIG_X86_CHECK_BIOS_CORRUPTION=y debug feature,
if similar bugs are suspected then this feature can be enabled on other
systems as well to scan low memory for corrupted memory.
Reported-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Reported-by: NAndy Wettstein <ajw1980@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When using kdump modifying the e820 map is yielding strange results.

For example starting with

 BIOS-provided physical RAM map:
 BIOS-e820: 0000000000000100 - 0000000000093400 (usable)
 BIOS-e820: 0000000000093400 - 00000000000a0000 (reserved)
 BIOS-e820: 0000000000100000 - 000000003fee0000 (usable)
 BIOS-e820: 000000003fee0000 - 000000003fef3000 (ACPI data)
 BIOS-e820: 000000003fef3000 - 000000003ff80000 (ACPI NVS)
 BIOS-e820: 000000003ff80000 - 0000000040000000 (reserved)
 BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved)
 BIOS-e820: 00000000fec00000 - 00000000fec10000 (reserved)
 BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
 BIOS-e820: 00000000ff000000 - 0000000100000000 (reserved)

and booting with args

memmap=exactmap memmap=640K@0K memmap=5228K@16384K memmap=125188K@22252K memmap=76K#1047424K memmap=564K#1047500K

resulted in:

 user-defined physical RAM map:
 user: 0000000000000000 - 0000000000093400 (usable)
 user: 0000000000093400 - 00000000000a0000 (reserved)
 user: 0000000000100000 - 000000003fee0000 (usable)
 user: 000000003fee0000 - 000000003fef3000 (ACPI data)
 user: 000000003fef3000 - 000000003ff80000 (ACPI NVS)
 user: 000000003ff80000 - 0000000040000000 (reserved)
 user: 00000000e0000000 - 00000000f0000000 (reserved)
 user: 00000000fec00000 - 00000000fec10000 (reserved)
 user: 00000000fee00000 - 00000000fee01000 (reserved)
 user: 00000000ff000000 - 0000000100000000 (reserved)

But should have resulted in:

 user-defined physical RAM map:
 user: 0000000000000000 - 00000000000a0000 (usable)
 user: 0000000001000000 - 000000000151b000 (usable)
 user: 00000000015bb000 - 0000000008ffc000 (usable)
 user: 000000003fee0000 - 000000003ff80000 (ACPI data)

This is happening because of an improper usage of strcmp() in the
e820 parsing code.  The strcmp() always returns !0 and never resets the
value for e820.nr_map and returns an incorrect user-defined map.

This patch fixes the problem.
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

It was introduced by "vsprintf: add support for '%pS' and '%pF' pointer
formats" in commit 0fe1ef24.  However,
the current way its coded doesn't work on parisc64.  For two reasons: 1)
parisc isn't in the #ifdef and 2) parisc has a different format for
function descriptors

Make dereference_function_descriptor() more accommodating by allowing
architecture overrides.  I put the three overrides (for parisc64, ppc64
and ia64) in arch/kernel/module.c because that's where the kernel
internal linker which knows how to deal with function descriptors sits.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NTony Luck <tony.luck@intel.com>
Acked-by: NKyle McMartin <kyle@mcmartin.ca>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When running a 31-bit ptrace, on either an s390 or s390x kernel,
reads and writes into a padding area in struct user_regs_struct32
will result in a kernel panic.

This is also known as CVE-2008-1514.

Test case available here:
http://sources.redhat.com/cgi-bin/cvsweb.cgi/~checkout~/tests/ptrace-tests/tests/user-area-padding.c?cvsroot=systemtap

Steps to reproduce:
1) wget the above
2) gcc -o user-area-padding-31bit user-area-padding.c -Wall -ggdb2 -D_GNU_SOURCE -m31
3) ./user-area-padding-31bit
<panic>

Test status
-----------
Without patch, both s390 and s390x kernels panic. With patch, the test case,
as well as the gdb testsuite, pass without incident, padding area reads
returning zero, writes ignored.

Nb: original version returned -EINVAL on write attempts, which broke the
gdb test and made the test case slightly unhappy, Jan Kratochvil suggested
the change to return 0 on write attempts.
Signed-off-by: NJarod Wilson <jarod@redhat.com>
Tested-by: NJan Kratochvil <jan.kratochvil@redhat.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When a CPU is offlined, we leave the timer interrupts disabled
because fixup_irqs() does not explicitly take care of that case.

Fix this by invoking tick_ops->disable_irq().

Based upon analysis done by Paul E. McKenney.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On 32-bit, at least the generic nops are fairly reasonable, but the
default nops for 64-bit really look pretty sad, and the P6 nops really do
look better.

So I would suggest perhaps moving the static P6 nop selection into the
CONFIG_X86_64 thing.

The alternative is to just get rid of that static nop selection, and just
have two cases: 32-bit and 64-bit, and just pick obviously safe cases for
them.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The second HPC3 could be found only on Guiness systems (Challenge-S),
but not on fullhouse (Indigo2) systems.
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

A make -j20 powerpc kernel build broke a couple of months ago saying:
In file included from arch/powerpc/boot/gunzip_util.h:13,
                 from arch/powerpc/boot/prpmc2800.c:21:
arch/powerpc/boot/zlib.h:85: error: expected ‘:’, ‘,’, ‘;’, ‘}’ or ‘__attribute__’ before ‘*’ token
arch/powerpc/boot/zlib.h:630: warning: type defaults to ‘int’ in declaration of ‘Byte’
arch/powerpc/boot/zlib.h:630: error: expected ‘;’, ‘,’ or ‘)’ before ‘*’ token

It happened again yesterday: too rare for me to confirm the fix, but
it looks like the list of dependants on gunzip_util.h was incomplete.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

We currently have a race when scheduling a context to a SPE -
after we have found a runnable context in spusched_tick, the same
context may have been scheduled by spu_activate().

This may result in a panic if we try to unschedule a context that has
been freed in the meantime.

This change exits spu_schedule() if the context has already been
scheduled, so we don't end up scheduling it twice.
Signed-off-by: NAndre Detsch <adetsch@br.ibm.com>
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>

Default the low memory corruption check to off, but make the default setting of
the memory_corruption_check kernel parameter a config parameter.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The corruption check is enabled in Kconfig by default, but disabled at runtime.

This patch adds several kernel parameters to control the corruption
check's behaviour; these are documented in kernel-parameters.txt.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Perodically check for corruption in low phusical memory.  Don't bother
checking at fault time, since it won't show anything useful.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Some BIOSes have been observed to corrupt memory in the low 64k.  This
change:
 - Reserves all memory which does not have to be in that area, to
   prevent it from being used as general memory by the kernel.  Things
   like the SMP trampoline are still in the memory, however.
 - Clears the reserved memory so we can observe changes to it.
 - Adds a function check_for_bios_corruption() which checks and reports on
   memory becoming unexpectedly non-zero.  Currently it's called in the
   x86 fault handler, and the powermanagement debug output.
Signed-off-by: NJeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Exception stacks are allocated each time a CPU is set online.
But the allocated space is never freed. Thus with one CPU hotplug
offline/online cycle there is a memory leak of 24K (6 pages) for
a CPU.

Fix is to allocate exception stacks only once -- when the CPU is
set online for the first time.
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Cc: akpm@linux-foundation.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

pda->irqstackptr is allocated whenever a CPU is set online.
But it is never freed. This results in a memory leak of 16K
for each CPU offline/online cycle.

Fix is to allocate pda->irqstackptr only once.
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Cc: akpm@linux-foundation.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Using native_pte_val triggers the BUG_ON() in the paravirt_ops
version of pte_flags().
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Acked-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Krzysztof Helt found MTRR is not detected on k6-2

root cause:
	we moved mtrr_bp_init() early for mtrr trimming,
and in early_detect we only read the CPU capability from cpuid,
so some cpu doesn't have that bit in cpuid.

So we need to add early_init_xxxx to preset those bit before mtrr_bp_init
for those earlier cpus.

this patch is for v2.6.27
Reported-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Move early cpu initialization after cpu early get cap so the
early cpu initialization can fix up cpu caps.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch provides an ARM implementation of ioremap_wc().

We use different page table attributes depending on which CPU we
are running on:

- Non-XScale ARMv5 and earlier systems: The ARMv5 ARM documents four
  possible mapping types (CB=00/01/10/11).  We can't use any of the
  cached memory types (CB=10/11), since that breaks coherency with
  peripheral devices.  Both CB=00 and CB=01 are suitable for _wc, and
  CB=01 (Uncached/Buffered) allows the hardware more freedom than
  CB=00, so we'll use that.

  (The ARMv5 ARM seems to suggest that CB=01 is allowed to delay stores
  but isn't allowed to merge them, but there is no other mapping type
  we can use that allows the hardware to delay and merge stores, so
  we'll go with CB=01.)

- XScale v1/v2 (ARMv5): same as the ARMv5 case above, with the slight
  difference that on these platforms, CB=01 actually _does_ allow
  merging stores.  (If you want noncoalescing bufferable behavior
  on Xscale v1/v2, you need to use XCB=101.)

- Xscale v3 (ARMv5) and ARMv6+: on these systems, we use TEXCB=00100
  mappings (Inner/Outer Uncacheable in xsc3 parlance, Uncached Normal
  in ARMv6 parlance).

  The ARMv6 ARM explicitly says that any accesses to Normal memory can
  be merged, which makes Normal memory more suitable for _wc mappings
  than Device or Strongly Ordered memory, as the latter two mapping
  types are guaranteed to maintain transaction number, size and order.
  We use the Uncached variety of Normal mappings for the same reason
  that we can't use C=1 mappings on ARMv5.

  The xsc3 Architecture Specification documents TEXCB=00100 as being
  Uncacheable and allowing coalescing of writes, which is also just
  what we need.
Signed-off-by: NLennert Buytenhek <buytenh@marvell.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

After fixing the u32 thinko I sill had occasional hickups on ATI chipsets
with small deltas. There seems to be a delay between writing the compare
register and the transffer to the internal register which triggers the
interrupt. Reading back the value makes sure, that it hit the internal
match register befor we compare against the counter value.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We use the HPET only in 32bit mode because:
1) some HPETs are 32bit only
2) on i386 there is no way to read/write the HPET atomic 64bit wide

The HPET code unification done by the "moron of the year" did
not take into account that unsigned long is different on 32 and
64 bit.

This thinko results in a possible endless loop in the clockevents
code, when the return comparison fails due to the 64bit/332bit
unawareness. 

unsigned long cnt = (u32) hpet_read() + delta can wrap over 32bit.
but the final compare will fail and return -ETIME causing endless
loops.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Use X86_FEATURE_NOPL to determine if it is safe to use P6 NOPs in
alternatives.  Also, replace table and loop with simple if statement.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The long noops ("NOPL") are supposed to be detected by family >= 6.
Unfortunately, several non-Intel x86 implementations, both hardware
and software, don't obey this dictum.  Instead, probe for NOPL
directly by executing a NOPL instruction and see if we get #UD.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The CPU feature detection code in the boot code is somewhat minimal,
and doesn't include all possible CPUID words.  In particular, it
doesn't contain the code for CPU feature words 2 (Transmeta),
3 (Linux-specific), 5 (VIA), or 7 (scattered).  Zero them out, so we
can still set those bits as known at compile time; in particular, this
allows creating a Linux-specific NOPL flag and have it required (and
therefore resolvable at compile time) in 64-bit mode.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Currently init_initrd() probes initrd header at the last page of kernel
image, but it is valid only if addinitrd was used.  If addinitrd was not
used, the area contains garbage so probing there might misdetect initrd
header (magic number is not strictly robust).

This patch introduces CONFIG_PROBE_INITRD_HEADER to explicitly enable this
probing.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Commmit 59e39ecd933ba49eb6efe84cbfa5597a6c9ef18a ("Fix WARNING: at
kernel/smp.c:290") introduced local_flush_icache_range but lacks
initialization for some TX39 case.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The txx9_pcode variable was introduced in commit
fe1c2bc64f65003b39f331a8e4b0d15b235a4afd ("TXx9: Add 64-bit support")
but was not initialized properly.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

trap_init issues flush_icache_range(), which uses ipi functions to
get icache flushing done on all cpus. But this is done before interrupts
are enabled and caused WARN_ON messages. This changeset introduces
a new local_flush_icache_range() and uses it before interrupts (and
additional CPUs) are enabled to avoid this problem.
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

With -ffunction-section the entries in __dbe_table aren't no longer
sorted, so the lookup of exception addresses in do_be() failed for
some addresses. To avoid this we now sort __dbe_table.
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This reverts commit ae82cbfc. It
needs the new byteorder headers to be exported to userspace, and
they aren't yet -- and probably shouldn't be, at this point in the
2.6.27 release cycle (or ever, for that matter).
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The minimum reprogramming delta was hardcoded in HPET ticks,
which is stupid as it does not work with faster running HPETs.
The C1E idle patches made this prominent on AMD/RS690 chipsets,
where the HPET runs with 25MHz. Set it to 5us which seems to be
a reasonable value and fixes the problems on the bug reporters
machines. We have a further sanity check now in the clock events,
which increases the delta when it is not sufficient.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NLuiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Tested-by: NDmitry Nezhevenko <dion@inhex.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Follows the SH change.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This patch fixes a problem within the SH implementation of resume_kernel code,
that implements in assembly the bulk of preempt_schedule_irq function without
taking care of the extra code needed to handle the BKL preemptible.

The patch basically consists of removing this asm code and calling the common
C implementation (see kernel/sched.c) as other archs do.

Another change is the missing 'cli' macro invocation at the beginning of
the resume_kernel.
Signed-off-by: NGiuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: NCarmelo Amoroso <carmelo.amoroso@st.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

We currently have a race for a free SPE. With one thread doing a
spu_yield(), and another doing a spu_activate():

thread 1				thread 2
spu_yield(oldctx)			spu_activate(ctx)
  __spu_deactivate(oldctx)
  spu_unschedule(oldctx, spu)
  spu->alloc_state = SPU_FREE
					spu = spu_get_idle(ctx)
					    - searches for a SPE in
					      state SPU_FREE, gets
					      the context just
					      freed by thread 1
					spu_schedule(ctx, spu)
					  spu->alloc_state = SPU_USED
spu_schedule(newctx, spu)
  - assumes spu is still free
  - tries to schedule context on
    already-used spu

This change introduces a 'free_spu' flag to spu_unschedule, to indicate
whether or not the function should free the spu after descheduling the
context. We only set this flag if we're not going to re-schedule
another context on this SPU.

Add a comment to document this behaviour.
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>

Commit 8d5636fb introduced a reference
count on SPU contexts during find_victim, but this may cause a leak in
the reference count if we later find a better contender for a context to
unschedule.

Change the reference to after we've found our victim context, so we
don't do the extra get_spu_context().
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>

mcbsp is confused as to what takes a physical or virtual address.
Fix the two instances where it gets it wrong.
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The driver(s) below do not use LINUX_VERSION_CODE nor KERNEL_VERSION.
  arch/arm/plat-mxc/clock.c

This patch removes the said #include <version.h>.
Signed-off-by: NHuang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>