CTX_VERSION_SHIFT   20 arch/sparc/include/asm/mmu_64.h #define CTX_VERSION_MASK	((~0UL) << CTX_VERSION_SHIFT)
CTX_VERSION_SHIFT   56 arch/sparc/include/asm/mmu_64.h #define CTX_FIRST_VERSION	BIT(CTX_VERSION_SHIFT)