linux-toradex.git/arch, branch v2.6.32.31

x86 quirk: Fix polarity for IRQ0 pin2 override on SB800 systems

2011-03-02T14:47:05+00:00

commit 7f74f8f28a2bd9db9404f7d364e2097a0c42cc12 upstream.

On some SB800 systems polarity for IOAPIC pin2 is wrongly
specified as low active by BIOS. This caused system hangs after
resume from S3 when HPET was used in one-shot mode on such
systems because a timer interrupt was missed (HPET signal is
high active).

For more details see:

  http://marc.info/?l=linux-kernel&m=129623757413868

Tested-by: Manoj Iyer 
Tested-by: Andre Przywara 
Signed-off-by: Andreas Herrmann 
Cc: Borislav Petkov 
LKML-Reference: <20110224145346.GD3658@alberich.amd.com>
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

ARM: Ensure predictable endian state on signal handler entry

2011-03-02T14:46:52+00:00

commit 53399053eb505cf541b2405bd9d9bca5ecfb96fb upstream.

Ensure a predictable endian state when entering signal handlers.  This
avoids programs which use SETEND to momentarily switch their endian
state from having their signal handlers entered with an unpredictable
endian state.

Acked-by: Dave Martin 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

s390: remove task_show_regs

2011-03-02T14:46:49+00:00

commit 261cd298a8c363d7985e3482946edb4bfedacf98 upstream.

task_show_regs used to be a debugging aid in the early bringup days
of Linux on s390. /proc//status is a world readable file, it
is not a good idea to show the registers of a process. The only
correct fix is to remove task_show_regs.

Reported-by: Al Viro 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

x86/pvclock: Zero last_value on resume

2011-03-02T14:46:36+00:00

commit e7a3481c0246c8e45e79c629efd63b168e91fcda upstream.

If the guest domain has been suspend/resumed or migrated, then the
system clock backing the pvclock clocksource may revert to a smaller
value (ie, can be non-monotonic across the migration/save-restore).

Make sure we zero last_value in that case so that the domain
continues to see clock updates.

Signed-off-by: Jeremy Fitzhardinge 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

x86, hpet: Disable per-cpu hpet timer if ARAT is supported

2011-03-02T14:46:35+00:00

commit 39fe05e58c5e448601ce46e6b03900d5bf31c4b0 upstream.

If CPU support always running local APIC timer, per-cpu hpet
timer could be disabled, which is useless and wasteful in such
case. Let's leave the timers to others.

The effect is that we reserve less timers.

Signed-off-by: Shaohua Li 
Cc: venkatesh.pallipadi@intel.com
LKML-Reference: <20090812031612.GA10062@sli10-desk.sh.intel.com>
Signed-off-by: Ingo Molnar 
Cc: Thomas Renninger 
Signed-off-by: Greg Kroah-Hartman

x86: Add IRQ_TIME_ACCOUNTING

2011-02-17T23:37:26+00:00

Commit: e82b8e4ea4f3dffe6e7939f90e78da675fcc450e upstream

This patch adds IRQ_TIME_ACCOUNTING option on x86 and runtime enables it
when TSC is enabled.

This change just enables fine grained irq time accounting, isn't used yet.
Following patches use it for different purposes.

Signed-off-by: Venkatesh Pallipadi 
Signed-off-by: Peter Zijlstra 
LKML-Reference: <1286237003-12406-6-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar 
Signed-off-by: Mike Galbraith 
Acked-by: Peter Zijlstra 
Signed-off-by: Greg Kroah-Hartman

sched: Consolidate account_system_vtime extern declaration

2011-02-17T23:37:24+00:00

Commit: e1e10a265d28273ab8c70be19d43dcbdeead6c5a upstream

Just a minor cleanup patch that makes things easier to the following patches.
No functionality change in this patch.

Signed-off-by: Venkatesh Pallipadi 
Signed-off-by: Peter Zijlstra 
LKML-Reference: <1286237003-12406-3-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar 
Signed-off-by: Mike Galbraith 
Acked-by: Peter Zijlstra 
Signed-off-by: Greg Kroah-Hartman

x86, mm: avoid possible bogus tlb entries by clearing prev mm_cpumask after switching mm

2011-02-17T23:37:18+00:00

commit 831d52bc153971b70e64eccfbed2b232394f22f8 upstream.

Clearing the cpu in prev's mm_cpumask early will avoid the flush tlb
IPI's while the cr3 is still pointing to the prev mm.  And this window
can lead to the possibility of bogus TLB fills resulting in strange
failures.  One such problematic scenario is mentioned below.

 T1. CPU-1 is context switching from mm1 to mm2 context and got a NMI
     etc between the point of clearing the cpu from the mm_cpumask(mm1)
     and before reloading the cr3 with the new mm2.

 T2. CPU-2 is tearing down a specific vma for mm1 and will proceed with
     flushing the TLB for mm1.  It doesn't send the flush TLB to CPU-1
     as it doesn't see that cpu listed in the mm_cpumask(mm1).

 T3. After the TLB flush is complete, CPU-2 goes ahead and frees the
     page-table pages associated with the removed vma mapping.

 T4. CPU-2 now allocates those freed page-table pages for something
     else.

 T5. As the CR3 and TLB caches for mm1 is still active on CPU-1, CPU-1
     can potentially speculate and walk through the page-table caches
     and can insert new TLB entries.  As the page-table pages are
     already freed and being used on CPU-2, this page walk can
     potentially insert a bogus global TLB entry depending on the
     (random) contents of the page that is being used on CPU-2.

 T6. This bogus TLB entry being global will be active across future CR3
     changes and can result in weird memory corruption etc.

To avoid this issue, for the prev mm that is handing over the cpu to
another mm, clear the cpu from the mm_cpumask(prev) after the cr3 is
changed.

Marking it for -stable, though we haven't seen any reported failure that
can be attributed to this.

Signed-off-by: Suresh Siddha 
Acked-by: Ingo Molnar 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

parisc : Remove broken line wrapping handling pdc_iodc_print()

2011-02-17T23:37:06+00:00

commit fbea668498e93bb38ac9226c7af9120a25957375 upstream.

Remove the broken line wrapping handling in pdc_iodc_print().
It is broken in 3 ways :
  - It doesn't keep track of the current screen position, it just
    assumes that the new buffer will be printed at the begining of the
    screen.
  - It doesn't take in account that non printable characters won't
    increase the current position on the screen.
  - And last but not least, it triggers a kernel panic if a backspace
    is the first char in the provided buffer :

 Backtrace:
  [<0000000040128ec4>] pdc_console_write+0x44/0x78
  [<0000000040128f18>] pdc_console_tty_write+0x20/0x38
  [<000000004032f1ac>] n_tty_write+0x2a4/0x550
  [<000000004032b158>] tty_write+0x1e0/0x2d8
  [<00000000401bb420>] vfs_write+0xb8/0x188
  [<00000000401bb630>] sys_write+0x68/0xb8
  [<0000000040104eb8>] syscall_exit+0x0/0x14

Most terminals handle the line wrapping just fine. I've confirmed that
it works correctly on a C8000 with both vga and serial output.

Signed-off-by: Guy Martin 
Signed-off-by: James Bottomley 
Signed-off-by: Greg Kroah-Hartman

powerpc: Fix some 6xx/7xxx CPU setup functions

2011-02-17T23:37:06+00:00

commit 1f1936ff3febf38d582177ea319eaa278f32c91f upstream.

Some of those functions try to adjust the CPU features, for example
to remove NAP support on some revisions. However, they seem to use
r5 as an index into the CPU table entry, which might have been right
a long time ago but no longer is. r4 is the right register to use.

This probably caused some off behaviours on some PowerMac variants
using 750cx or 7455 processor revisions.

Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman