diff options
Diffstat (limited to 'arch/powerpc/include/asm/mmu_context.h')
| -rw-r--r-- | arch/powerpc/include/asm/mmu_context.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index 360367c579de..1a474f6b1992 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -185,11 +185,41 @@ static inline void mm_context_remove_copro(struct mm_struct *mm) dec_mm_active_cpus(mm); } } + +/* + * vas_windows counter shows number of open windows in the mm + * context. During context switch, use this counter to clear the + * foreign real address mapping (CP_ABORT) for the thread / process + * that intend to use COPY/PASTE. When a process closes all windows, + * disable CP_ABORT which is expensive to run. + * + * For user context, register a copro so that TLBIs are seen by the + * nest MMU. mm_context_add/remove_vas_window() are used only for user + * space windows. + */ +static inline void mm_context_add_vas_window(struct mm_struct *mm) +{ + atomic_inc(&mm->context.vas_windows); + mm_context_add_copro(mm); +} + +static inline void mm_context_remove_vas_window(struct mm_struct *mm) +{ + int v; + + mm_context_remove_copro(mm); + v = atomic_dec_if_positive(&mm->context.vas_windows); + + /* Detect imbalance between add and remove */ + WARN_ON(v < 0); +} #else static inline void inc_mm_active_cpus(struct mm_struct *mm) { } static inline void dec_mm_active_cpus(struct mm_struct *mm) { } static inline void mm_context_add_copro(struct mm_struct *mm) { } static inline void mm_context_remove_copro(struct mm_struct *mm) { } +static inline void mm_context_add_vas_windows(struct mm_struct *mm) { } +static inline void mm_context_remove_vas_windows(struct mm_struct *mm) { } #endif |