Context switch improvements

Here are various improvements to our context switch path. Some of the highlights:

- Group all mfsprs and mtsprs in __switch_to(), which gives us a 10% improvement on POWER8.

- Create giveup_all() and flush_all_to_thread() so we only write the MSR once, which gives us a 3% improvement on POWER8.

- Create disable_kernel_{fp,altivec,vsx,spe}() and add a debug boot option (ppc_strict_facility_enable) to minimise kernel code running with floating point and vector bits enabled.

- Make giveup_vsx() and flush_vsx_to_thread() handle FP and Altivec state, so they behave more like their sister functions.

Scott: There are changes to the SPE code here which I have only been able to compile test.

Anton
--

Anton Blanchard (19):
powerpc: Don't disable kernel FP/VMX/VSX MSR bits on context switch
powerpc: Don't disable MSR bits in do_load_up_transact_*() functions
powerpc: Create context switch helpers save_sprs() and restore_sprs()
powerpc: Remove redundant mflr in _switch
powerpc: Remove UP only lazy floating point and vector optimisations
powerpc: Simplify TM restore checks
powerpc: Create mtmsrd_isync()
powerpc: Remove NULL task struct pointer checks in FP and vector code
powerpc: Move part of giveup_fpu,altivec,spe into c
powerpc: Move part of giveup_vsx into c
crypto: vmx: Only call enable_kernel_vsx()
powerpc: Create msr_check_and_{set,clear}()
powerpc: Create disable_kernel_{fp,altivec,vsx,spe}()
powerpc: Add ppc_strict_facility_enable boot option
powerpc: Remove fp_enable() and vec_enable(), use

    msr_check_and_{set,clear}()

powerpc: create giveup_all()
powerpc: create flush_all_to_thread()
powerpc: Rearrange __switch_to()
powerpc: clean up asm/switch_to.h

 Documentation/kernel-parameters.txt      |   6 +
 arch/powerpc/crypto/aes-spe-glue.c       |   1 +
 arch/powerpc/crypto/sha1-spe-glue.c      |   1 +
 arch/powerpc/crypto/sha256-spe-glue.c    |   1 +
 arch/powerpc/include/asm/processor.h     |   9 +-
 arch/powerpc/include/asm/reg.h           |  17 ++
 arch/powerpc/include/asm/switch_to.h     |  65 ++---
 arch/powerpc/kernel/align.c              |   2 +
 arch/powerpc/kernel/entry_64.S           |  75 +----
 arch/powerpc/kernel/fpu.S                |  73 +----
 arch/powerpc/kernel/head_fsl_booke.S     |  42 +--
 arch/powerpc/kernel/idle_power7.S        |   7 -
 arch/powerpc/kernel/ppc_ksyms.c          |   6 -
 arch/powerpc/kernel/process.c            | 471 ++++++++++++++++++-------------
 arch/powerpc/kernel/signal_32.c          |  22 +-
 arch/powerpc/kernel/signal_64.c          |  22 +-
 arch/powerpc/kernel/swsusp.c             |   4 +-
 arch/powerpc/kernel/vector.S             | 112 +-------
 arch/powerpc/kvm/book3s_hv.c             |   5 +-
 arch/powerpc/kvm/book3s_paired_singles.c |   1 +
 arch/powerpc/kvm/book3s_pr.c             |  21 +-
 arch/powerpc/kvm/booke.c                 |   4 +
 arch/powerpc/lib/vmx-helper.c            |   2 +
 arch/powerpc/lib/xor_vmx.c               |   4 +
 drivers/crypto/vmx/aes.c                 |   6 +-
 drivers/crypto/vmx/aes_cbc.c             |   6 +-
 drivers/crypto/vmx/aes_ctr.c             |   6 +-
 drivers/crypto/vmx/ghash.c               |  12 +-
 lib/raid6/altivec.uc                     |   1 +
 29 files changed, 376 insertions(+), 628 deletions(-)

2.5.0