linux-toradex.git/arch/powerpc/kernel/process.c, branch v3.5-rc2

Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-05-23T17:59:07+00:00

Pull fpu state cleanups from Ingo Molnar:
 "This tree streamlines further aspects of FPU handling by eliminating
  the prepare_to_copy() complication and moving that logic to
  arch_dup_task_struct().

  It also fixes the FPU dumps in threaded core dumps, removes and old
  (and now invalid) assumption plus micro-optimizes the exit path by
  avoiding an FPU save for dead tasks."

Fixed up trivial add-add conflict in arch/sh/kernel/process.c that came
in because we now do the FPU handling in arch_dup_task_struct() rather
than the legacy (and now gone) prepare_to_copy().

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, fpu: drop the fpu state during thread exit
  x86, xsave: remove thread_has_fpu() bug check in __sanitize_i387_state()
  coredump: ensure the fpu state is flushed for proper multi-threaded core dump
  fork: move the real prepare_to_copy() users to arch_dup_task_struct()

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

2012-05-23T16:02:42+00:00

Pull powerpc updates from Benjamin Herrenschmidt:
 "Here are the powerpc goodies for 3.5.  Main highlights are:

   - Support for the NX crypto engine in Power7+
   - A bunch of Anton goodness, including some micro optimization of our
     syscall entry on Power7
   - I converted a pile of our thermal control drivers to the new i2c
     APIs (essentially turning the old therm_pm72 into a proper set of
     windfarm drivers).  That's one more step toward removing the
     deprecated i2c APIs, there's still a few drivers to fix, but we are
     getting close
   - kexec/kdump support for 47x embedded cores

  The big missing thing here is no updates from Freescale.  Not sure
  what's up here, but with Kumar not working for them anymore things are
  a bit in a state of flux in that area."

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (71 commits)
  powerpc: Fix irq distribution
  Revert "powerpc/hw-breakpoint: Use generic hw-breakpoint interfaces for new PPC ptrace flags"
  powerpc: Fixing a cputhread code documentation
  powerpc/crypto: Enable the PFO-based encryption device
  powerpc/crypto: Build files for the nx device driver
  powerpc/crypto: debugfs routines and docs for the nx device driver
  powerpc/crypto: SHA512 hash routines for nx encryption
  powerpc/crypto: SHA256 hash routines for nx encryption
  powerpc/crypto: AES-XCBC mode routines for nx encryption
  powerpc/crypto: AES-GCM mode routines for nx encryption
  powerpc/crypto: AES-ECB mode routines for nx encryption
  powerpc/crypto: AES-CTR mode routines for nx encryption
  powerpc/crypto: AES-CCM mode routines for nx encryption
  powerpc/crypto: AES-CBC mode routines for nx encryption
  powerpc/crypto: nx driver code supporting nx encryption
  powerpc/pseries: Enable the PFO-based RNG accelerator
  powerpc/pseries/hwrng: PFO-based hwrng driver
  powerpc/pseries: Add PFO support to the VIO bus
  powerpc/pseries: Add pseries update notifier for OFDT prop changes
  powerpc/pseries: Add new hvcall constants to support PFO
  ...

fork: move the real prepare_to_copy() users to arch_dup_task_struct()

2012-05-16T22:16:26+00:00

Historical prepare_to_copy() is mostly a no-op, duplicated for majority of
the architectures and the rest following the x86 model of flushing the extended
register state like fpu there.

Remove it and use the arch_dup_task_struct() instead.

Suggested-by: Oleg Nesterov 
Suggested-by: Linus Torvalds 
Signed-off-by: Suresh Siddha 
Link: http://lkml.kernel.org/r/1336692811-30576-1-git-send-email-suresh.b.siddha@intel.com
Acked-by: Benjamin Herrenschmidt 
Cc: David Howells 
Cc: Koichi Yasutake 
Cc: Paul Mackerras 
Cc: Paul Mundt 
Cc: Chris Zankel 
Cc: Richard Henderson 
Cc: Russell King 
Cc: Haavard Skinnemoen 
Cc: Mike Frysinger 
Cc: Mark Salter 
Cc: Aurelien Jacquiot 
Cc: Mikael Starvik 
Cc: Yoshinori Sato 
Cc: Richard Kuo 
Cc: Tony Luck 
Cc: Michal Simek 
Cc: Ralf Baechle 
Cc: Jonas Bonn 
Cc: James E.J. Bottomley 
Cc: Helge Deller 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Chen Liqin 
Cc: Lennox Wu 
Cc: David S. Miller 
Cc: Chris Metcalf 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Guan Xuetao 
Signed-off-by: H. Peter Anvin

powerpc: Use common threadinfo allocator

2012-05-08T12:08:45+00:00

The core now has a threadinfo allocator which uses a kmemcache when
THREAD_SIZE < PAGE_SIZE.

Signed-off-by: Thomas Gleixner 
Cc: Benjamin Herrenschmidt 
Link: http://lkml.kernel.org/r/20120505150142.059161130@linutronix.de

powerpc: Optimise enable_kernel_altivec

2012-04-30T05:37:17+00:00

Add two optimisations to enable_kernel_altivec:

- enable_kernel_altivec has already determined if we need to
save the previous task's state but we call giveup_altivec
in both cases, requiring an extra branch in giveup_altivec. Create
giveup_altivec_notask which only turns on the VMX bit in the
MSR.

- We write the VMX MSR bit each time we call enable_kernel_altivec
even it was already set. Check the bit and branch out if we have
already set it. The classic case for this is vectored IO
where we have to copy multiple buffers to or from userspace.

The following testcase was used to confirm this patch improves
performance:

http://ozlabs.org/~anton/junkcode/copy_to_user.c

Since the current breakpoint for using VMX in copy_tofrom_user is
4096 bytes, I'm using buffers of 4096 + 1 cacheline (4224) bytes.
A benchmark of 16 entry readvs (-s 16):

time copy_to_user -l 4224 -s 16 -i 1000000

completes 5.2% faster on a POWER7 PS700.

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix typo in runlatch code

2012-04-11T00:42:15+00:00

Commit fe1952fc0afb9a2e4c79f103c08aef5d13db1873
"powerpc: Rework runlatch code" has a nasty typo
where it uses "TLF_RUNLATCH" instead of "_TLF_RUNLATCH"
(bit number instead of bit mask), causing some flags to
be potentially lost such as _TLF_RESTORE_SIGMASK

(Brown paper bag for me ! We should be able to make
that break at compile time with a bit of magic, any
volunteer ?)

Signed-off-by: Benjamin Herrenschmidt

Disintegrate asm/system.h for PowerPC

2012-03-28T17:30:02+00:00

Disintegrate asm/system.h for PowerPC.

Signed-off-by: David Howells 
Acked-by: Benjamin Herrenschmidt 
cc: linuxppc-dev@lists.ozlabs.org

powerpc: Rework lazy-interrupt handling

2012-03-09T02:25:06+00:00

The current implementation of lazy interrupts handling has some
issues that this tries to address.

We don't do the various workarounds we need to do when re-enabling
interrupts in some cases such as when returning from an interrupt
and thus we may still lose or get delayed decrementer or doorbell
interrupts.

The current scheme also makes it much harder to handle the external
"edge" interrupts provided by some BookE processors when using the
EPR facility (External Proxy) and the Freescale Hypervisor.

Additionally, we tend to keep interrupts hard disabled in a number
of cases, such as decrementer interrupts, external interrupts, or
when a masked decrementer interrupt is pending. This is sub-optimal.

This is an attempt at fixing it all in one go by reworking the way
we do the lazy interrupt disabling from the ground up.

The base idea is to replace the "hard_enabled" field with a
"irq_happened" field in which we store a bit mask of what interrupt
occurred while soft-disabled.

When re-enabling, either via arch_local_irq_restore() or when returning
from an interrupt, we can now decide what to do by testing bits in that
field.

We then implement replaying of the missed interrupts either by
re-using the existing exception frame (in exception exit case) or via
the creation of a new one from an assembly trampoline (in the
arch_local_irq_enable case).

This removes the need to play with the decrementer to try to create
fake interrupts, among others.

In addition, this adds a few refinements:

 - We no longer  hard disable decrementer interrupts that occur
while soft-disabled. We now simply bump the decrementer back to max
(on BookS) or leave it stopped (on BookE) and continue with hard interrupts
enabled, which means that we'll potentially get better sample quality from
performance monitor interrupts.

 - Timer, decrementer and doorbell interrupts now hard-enable
shortly after removing the source of the interrupt, which means
they no longer run entirely hard disabled. Again, this will improve
perf sample quality.

 - On Book3E 64-bit, we now make the performance monitor interrupt
act as an NMI like Book3S (the necessary C code for that to work
appear to already be present in the FSL perf code, notably calling
nmi_enter instead of irq_enter). (This also fixes a bug where BookE
perfmon interrupts could clobber r14 ... oops)

 - We could make "masked" decrementer interrupts act as NMIs when doing
timer-based perf sampling to improve the sample quality.

Signed-off-by-yet: Benjamin Herrenschmidt 
---

v2:

- Add hard-enable to decrementer, timer and doorbells
- Fix CR clobber in masked irq handling on BookE
- Make embedded perf interrupt act as an NMI
- Add a PACA_HAPPENED_EE_EDGE for use by FSL if they want
  to retrigger an interrupt without preventing hard-enable

v3:

 - Fix or vs. ori bug on Book3E
 - Fix enabling of interrupts for some exceptions on Book3E

v4:

 - Fix resend of doorbells on return from interrupt on Book3E

v5:

 - Rebased on top of my latest series, which involves some significant
rework of some aspects of the patch.

v6:
 - 32-bit compile fix
 - more compile fixes with various .config combos
 - factor out the asm code to soft-disable interrupts
 - remove the C wrapper around preempt_schedule_irq

v7:
 - Fix a bug with hard irq state tracking on native power7

powerpc: Rework runlatch code

2012-03-08T23:55:02+00:00

This moves the inlines into system.h and changes the runlatch
code to use the thread local flags (non-atomic) rather than
the TIF flags (atomic) to keep track of the latch state.

The code to turn it back on in an asynchronous interrupt is
now simplified and partially inlined.

Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix kernel log of oops/panic instruction dump

2012-02-16T05:11:23+00:00

A kernel oops/panic prints an instruction dump showing several
instructions before and after the instruction which caused the
oops/panic.

The code intended that the faulting instruction be enclosed in angle
brackets, however a bug caused the faulting instruction to be
interpreted by printk() as the message log level.

To fix this, the KERN_CONT log level is added before the actual text of
the printed message.

=== Before the patch ===

[ 1081.587266] Instruction dump:
[ 1081.590236] 7c000110 7c0000f8 5400077c 552907f6 7d290378 992b0003 4e800020 38000001
[ 1081.598034] 3d20c03a 9009a114 7c0004ac 39200000
[ 1081.602500]  4e800020 3803ffd0 2b800009

<4>[ 1081.587266] Instruction dump:
<4>[ 1081.590236] 7c000110 7c0000f8 5400077c 552907f6 7d290378 992b0003 4e800020 38000001
<4>[ 1081.598034] 3d20c03a 9009a114 7c0004ac 39200000
<98090000>[ 1081.602500]  4e800020 3803ffd0 2b800009

=== After the patch ===

[   51.385216] Instruction dump:
[   51.388186] 7c000110 7c0000f8 5400077c 552907f6 7d290378 992b0003 4e800020 38000001
[   51.395986] 3d20c03a 9009a114 7c0004ac 39200000 <98090000> 4e800020 3803ffd0 2b800009

<4>[   51.385216] Instruction dump:
<4>[   51.388186] 7c000110 7c0000f8 5400077c 552907f6 7d290378 992b0003 4e800020 38000001
<4>[   51.395986] 3d20c03a 9009a114 7c0004ac 39200000 <98090000> 4e800020 3803ffd0 2b800009

Signed-off-by: Ira W. Snyder 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Benjamin Herrenschmidt