[PATCH v4 0/4] powerpc/sstep: VSX 32-byte vector paired load/store instructions

[Ravi Bangoria <ravi.bangoria@linux.ibm.com>]

VSX vector paired instructions operates with octword (32-byte)
operand for loads and stores between storage and a pair of two
sequential Vector-Scalar Registers (VSRs). There are 4 word
instructions and 2 prefixed instructions that provides this
32-byte storage access operations - lxvp, lxvpx, stxvp, stxvpx,
plxvp, pstxvp.

Emulation infrastructure doesn't have support for these instructions,
to operate with 32-byte storage access and to operate with 2 VSX
registers. This patch series enables the instruction emulation
support and adds test cases for them respectively.

v3: https://lore.kernel.org/linuxppc-dev/20200731081637.1837559-1-bala24@linux.ibm.com/ 

Changes in v4:
-------------
* Patch #1 is (kind of) new.
* Patch #2 now enables both analyse_instr() and emulate_step()
  unlike prev series where both were in separate patches.
* Patch #2 also has important fix for emulation on LE.
* Patch #3 and #4. Added XSP/XTP, D0/D1 instruction operands,
  removed *_EX_OP, __PPC_T[P][X] macros which are incorrect,
  and adhered to PPC_RAW_* convention.
* Added `CPU_FTR_ARCH_31` check in testcases to avoid failing
  in p8/p9.
* Some consmetic changes.
* Rebased to powerpc/next

Changes in v3:
-------------
Worked on review comments and suggestions from Ravi and Naveen,

* Fix the do_vsx_load() to handle vsx instructions if MSR_FP/MSR_VEC
  cleared in exception conditions and it reaches to read/write to
  thread_struct member fp_state/vr_state respectively.
* Fix wrongly used `__vector128 v[2]` in struct vsx_reg as it should
  hold a single vsx register size.
* Remove unnecessary `VSX_CHECK_VEC` flag set and condition to check
  `VSX_LDLEFT` that is not applicable for these vsx instructions.
* Fix comments in emulate_vsx_load() that were misleading.
* Rebased on latest powerpc next branch.

Changes in v2:
-------------
* Fix suggestion from Sandipan, wrap ISA 3.1 instructions with
  cpu_has_feature(CPU_FTR_ARCH_31) check.
* Rebase on latest powerpc next branch.


Balamuruhan S (4):
  powerpc/sstep: Emulate prefixed instructions only when CPU_FTR_ARCH_31
    is set
  powerpc/sstep: Support VSX vector paired storage access instructions
  powerpc/ppc-opcode: Add encoding macros for VSX vector paired
    instructions
  powerpc/sstep: Add testcases for VSX vector paired load/store
    instructions

 arch/powerpc/include/asm/ppc-opcode.h |  13 ++
 arch/powerpc/lib/sstep.c              | 152 +++++++++++++--
 arch/powerpc/lib/test_emulate_step.c  | 270 ++++++++++++++++++++++++++
 3 files changed, 414 insertions(+), 21 deletions(-)

-- 
2.26.2