[PATCH 4.14 43/44] powerpc/powernv: Fix save/restore of SPRG3 on entry/exit from stop (idle)

4.14-stable review patch. If anyone has any objections, please let me know. -- From: Gautham R. Shenoy commit b03897cf318dfc47de33a7ecbc7655584266f034 upstream. On 64-bit servers, SPRN_SPRG3 and its userspace read-only mirror SPRN_USPRG3 are used as userspace VDSO write and

[PATCH 4.14 43/44] powerpc/powernv: Fix save/restore of SPRG3 on entry/exit from stop (idle)

4.14-stable review patch. If anyone has any objections, please let me know. -- From: Gautham R. Shenoy commit b03897cf318dfc47de33a7ecbc7655584266f034 upstream. On 64-bit servers, SPRN_SPRG3 and its userspace read-only mirror SPRN_USPRG3 are used as userspace VDSO write and