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    • Linus Torvalds's avatar
      x86, tsc: Fix SMI induced variation in quick_pit_calibrate() · 68f30fbe
      Linus Torvalds authored 
      

pit_expect_msb() returns success wrongly in the below SMI scenario:

a. pit_verify_msb() has not yet seen the MSB transition.

b. we are close to the MSB transition though and got a SMI immediately after
   returning from pit_verify_msb() which didn't see the MSB transition. PIT MSB
   transition has happened somewhere during SMI execution.

c. returned from SMI and we noted down the 'tsc', saw the pit MSB change now and
   exited the loop to calculate 'deltatsc'. Instead of noting the TSC at the MSB
   transition, we are way off because of the SMI.  And as the SMI happened
   between the pit_verify_msb() and before the 'tsc' is recorded in the
   for loop, 'delattsc' (d1/d2 in quick_pit_calibrate()) will be small and
   quick_pit_calibrate() will not notice this error.

Depending on whether SMI disturbance happens while computing d1 or d2, we will
see the TSC calibrated value smaller or bigger than the expected value. As a
result, in a cluster we were seeing a variation of approximately +/- 20MHz in
the calibrated values, resulting in NTP failures.

  [ As far as the SMI source is concerned, this is a periodic SMI that gets
    disabled after ACPI is enabled by the OS. But the TSC calibration happens
    before the ACPI is enabled. ]

To address this, change pit_expect_msb() so that

 - the 'tsc' is the TSC in between the two reads that read the MSB
change from the PIT (same as before)

 - the 'delta' is the difference in TSC from *before* the MSB changed
to *after* the MSB changed.

Now the delta is twice as big as before (it covers four PIT accesses,
roughly 4us) and quick_pit_calibrate() will loop a bit longer to get
the calibrated value with in the 500ppm precision. As the delta (d1/d2)
covers four PIT accesses, actual calibrated result might be closer to
250ppm precision.

As the loop now takes longer to stabilize, double MAX_QUICK_PIT_MS to 50.

SMI disturbance will showup as much larger delta's and the loop will take
longer than usual for the result to be with in the accepted precision. Or will
fallback to slow PIT calibration if it takes more than 50msec.

Also while we are at this, remove the calibration correction that aims to
get the result to the middle of the error bars. We really don't know which
direction to correct into, so remove it.

Reported-and-tested-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1326843337.5291.4.camel@sbsiddha-mobl2


Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      68f30fbe
    • Eric Paris's avatar
      audit: inline audit_syscall_entry to reduce burden on archs · b05d8447
      Eric Paris authored 
      

Every arch calls:

if (unlikely(current->audit_context))
	audit_syscall_entry()

which requires knowledge about audit (the existance of audit_context) in
the arch code.  Just do it all in static inline in audit.h so that arch's
can remain blissfully ignorant.

Signed-off-by: default avatarEric Paris <eparis@redhat.com>
      b05d8447
    • Eric Paris's avatar
      audit: ia32entry.S sign extend error codes when calling 64 bit code · f031cd25
      Eric Paris authored 
      

In the ia32entry syscall exit audit fastpath we have assembly code which calls
__audit_syscall_exit directly.  This code was, however, zeroes the upper 32
bits of the return code.  It then proceeded to call code which expects longs
to be 64bits long.  In order to handle code which expects longs to be 64bit we
sign extend the return code if that code is an error.  Thus the
__audit_syscall_exit function can correctly handle using the values in
snprintf("%ld").  This fixes the regression introduced in 5cbf1565.

Old record:
type=SYSCALL msg=audit(1306197182.256:281): arch=40000003 syscall=192 success=no exit=4294967283
New record:
type=SYSCALL msg=audit(1306197182.256:281): arch=40000003 syscall=192 success=no exit=-13

Signed-off-by: default avatarEric Paris <eparis@redhat.com>
Acked-by: default avatarH. Peter Anvin <hpa@zytor.com>
      f031cd25
    • Eric Paris's avatar
      Audit: push audit success and retcode into arch ptrace.h · d7e7528b
      Eric Paris authored 
      

The audit system previously expected arches calling to audit_syscall_exit to
supply as arguments if the syscall was a success and what the return code was.
Audit also provides a helper AUDITSC_RESULT which was supposed to simplify things
by converting from negative retcodes to an audit internal magic value stating
success or failure.  This helper was wrong and could indicate that a valid
pointer returned to userspace was a failed syscall.  The fix is to fix the
layering foolishness.  We now pass audit_syscall_exit a struct pt_reg and it
in turns calls back into arch code to collect the return value and to
determine if the syscall was a success or failure.  We also define a generic
is_syscall_success() macro which determines success/failure based on if the
value is < -MAX_ERRNO.  This works for arches like x86 which do not use a
separate mechanism to indicate syscall failure.

We make both the is_syscall_success() and regs_return_value() static inlines
instead of macros.  The reason is because the audit function must take a void*
for the regs.  (uml calls theirs struct uml_pt_regs instead of just struct
pt_regs so audit_syscall_exit can't take a struct pt_regs).  Since the audit
function takes a void* we need to use static inlines to cast it back to the
arch correct structure to dereference it.

The other major change is that on some arches, like ia64, MIPS and ppc, we
change regs_return_value() to give us the negative value on syscall failure.
THE only other user of this macro, kretprobe_example.c, won't notice and it
makes the value signed consistently for the audit functions across all archs.

In arch/sh/kernel/ptrace_64.c I see that we were using regs[9] in the old
audit code as the return value.  But the ptrace_64.h code defined the macro
regs_return_value() as regs[3].  I have no idea which one is correct, but this
patch now uses the regs_return_value() function, so it now uses regs[3].

For powerpc we previously used regs->result but now use the
regs_return_value() function which uses regs->gprs[3].  regs->gprs[3] is
always positive so the regs_return_value(), much like ia64 makes it negative
before calling the audit code when appropriate.

Signed-off-by: default avatarEric Paris <eparis@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com> [for x86 portion]
Acked-by: Tony Luck <tony.luck@intel.com> [for ia64]
Acked-by: Richard Weinberger <richard@nod.at> [for uml]
Acked-by: David S. Miller <davem@davemloft.net> [for sparc]
Acked-by: Ralf Baechle <ralf@linux-mips.org> [for mips]
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [for ppc]
      d7e7528b
    • Ulrich Drepper's avatar
      x86, opcode: ANDN and Group 17 in x86-opcode-map.txt · ce79dac8
      Ulrich Drepper authored 
      The Intel documentation at

http://software.intel.com/file/36945



shows the ANDN opcode and Group 17 with encoding f2 and f3 encoding
respectively.  The current version of x86-opcode-map.txt shows them
with f3 and f4.  Unless someone can point to documentation which shows
the currently used encoding the following patch be applied.

Signed-off-by: default avatarUlrich Drepper <drepper@gmail.com>
Link: http://lkml.kernel.org/r/CAOPLpQdq5SuVo9=023CYhbFLAX9rONyjmYq7jJkqc5xwctW5eA@mail.gmail.com


Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
      ce79dac8
    • Randy Dunlap's avatar
      x86/kconfig: Move the ZONE_DMA entry under a menu · 5ee71535
      Randy Dunlap authored 
      

Move the ZONE_DMA kconfig symbol under a menu item instead
of having it listed before everything else in
"make {xconfig | gconfig | nconfig | menuconfig}".

This drops the first line of the top-level kernel config menu
(in 3.2) below and moves it under "Processor type and features".

          [*] DMA memory allocation support
              General setup  --->
          [*] Enable loadable module support  --->
          [*] Enable the block layer  --->
              Processor type and features  --->
              Power management and ACPI options  --->
              Bus options (PCI etc.)  --->
              Executable file formats / Emulations  --->

Signed-off-by: default avatarRandy Dunlap <rdunlap@xenotime.net>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-mm@kvack.org <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/4F14811E.6090107@xenotime.net


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: David Rientjes <rientjes@google.com>
      5ee71535
    • Kurt Garloff's avatar
      ACPI, x86: Use SRAT table rev to use 8bit or 32bit PXM fields (x86/x86-64) · cd298f60
      Kurt Garloff authored 
      

In SRAT v1, we had 8bit proximity domain (PXM) fields; SRAT v2 provides
32bits for these. The new fields were reserved before.
According to the ACPI spec, the OS must disregrard reserved fields.

x86/x86-64 was rather inconsistent prior to this patch; it used 8 bits
for the pxm field in cpu_affinity, but 32 bits in mem_affinity.
This patch makes it consistent: Either use 8 bits consistently (SRAT
rev 1 or lower) or 32 bits (SRAT rev 2 or higher).

cc: x86@kernel.org
Signed-off-by: default avatarKurt Garloff <kurt@garloff.de>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      cd298f60
    • Huang Ying's avatar
      ACPI, Record ACPI NVS regions · b54ac6d2
      Huang Ying authored 
      

Some firmware will access memory in ACPI NVS region via APEI.  That
is, instructions in APEI ERST/EINJ table will read/write ACPI NVS
region.  The original resource conflict checking in APEI code will
check memory/ioport accessed by APEI via general resource management
mechanism.  But ACPI NVS region is marked as busy already, so that the
false resource conflict will prevent APEI ERST/EINJ to work.

To fix this, this patch record ACPI NVS regions, so that we can avoid
request resources for memory region inside it.

Signed-off-by: default avatarHuang Ying <ying.huang@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      b54ac6d2
    • Cliff Wickman's avatar
      x86/UV2: Add accounting for BAU strong nacks · b54bd9be
      Cliff Wickman authored 
      

This patch adds separate accounting of UV2 message "strong
nack's" in the BAU statistics.

Signed-off-by: default avatarCliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116212238.GF5767@sgi.com


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      b54bd9be
    • Cliff Wickman's avatar
      x86/UV2: Ack BAU interrupt earlier · 88ed9dd7
      Cliff Wickman authored 
      

This patch moves the ack of the BAU interrupt to the beginning
of  the interrupt handler so that there is less possibility of a
lost interrupt and slower response to a shootdown message.

Signed-off-by: default avatarCliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116212146.GE5767@sgi.com


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      88ed9dd7
    • Cliff Wickman's avatar
      x86/UV2: Remove stale no-resources test for UV2 BAU · 478c6e52
      Cliff Wickman authored 
      

This patch removes an unnecessary test for a
no-destination-resources-available condition that looks like a
destination timeout in UV1, but is separately distinguishable in
UV2.

Signed-off-by: default avatarCliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116212050.GD5767@sgi.com


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      478c6e52
    • Cliff Wickman's avatar
      x86/UV2: Work around BAU bug · c5d35d39
      Cliff Wickman authored 
      

This patch implements a workaround for a UV2 hardware bug.
The bug is a non-atomic update of a memory-mapped register. When
hardware message delivery and software message acknowledge occur
simultaneously the pending message acknowledge for the arriving
message may be lost.  This causes the sender's message status to
stay busy.

Part of the workaround is to not acknowledge a completed message
until it is verified that no other message is actually using the
resource that is mistakenly recorded in the completed message.

Part of the workaround is to test for long elapsed time in such
a busy condition, then handle it by using a spare sending
descriptor. The stay-busy condition is eventually timed out by
hardware, and then the original sending descriptor can be
re-used. Most of that logic change is in keeping track of the
current descriptor and the state of the spares.

The occurrences of the workaround are added to the BAU
statistics.

Signed-off-by: default avatarCliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116211947.GC5767@sgi.com


Cc: <stable@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      c5d35d39
    • Cliff Wickman's avatar
      x86/UV2: Fix BAU destination timeout initialization · d059f9fa
      Cliff Wickman authored 
      

Move the call to enable_timeouts() forward so that
BAU_MISC_CONTROL is initialized before using it in
calculate_destination_timeout().

Fix the calculation of a BAU destination timeout
for UV2 (in calculate_destination_timeout()).

Signed-off-by: default avatarCliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116211848.GB5767@sgi.com


Cc: <stable@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      d059f9fa
    • Cliff Wickman's avatar
      x86/UV2: Fix new UV2 hardware by using native UV2 broadcast mode · da87c937
      Cliff Wickman authored 
      

Update the use of the Broadcast Assist Unit on SGI Altix UV2 to
the use of native UV2 mode on new hardware (not the legacy mode).

UV2 native mode has a different format for a broadcast message.
We also need quick differentiaton between UV1 and UV2.

Signed-off-by: default avatarCliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116211750.GA5767@sgi.com


Cc: <stable@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      da87c937
    • Greg Kroah-Hartman's avatar
      mce: fix warning messages about static struct mce_device · e032d807
      Greg Kroah-Hartman authored 
      

When suspending, there was a large list of warnings going something like:

	Device 'machinecheck1' does not have a release() function, it is broken and must be fixed

This patch turns the static mce_devices into dynamically allocated, and
properly frees them when they are removed from the system.  It solves
the warning messages on my laptop here.

Reported-by: default avatar"Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Tested-by: default avatarDjalal Harouni <tixxdz@opendz.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@amd64.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e032d807
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