Re: [PATCH v3 03/23] arc: use asm-generic/mmu_context.h for no-op implementations

Vineet Gupta
2020-09-01T18:32:29Z

On 9/1/20 7:15 AM, Nicholas Piggin wrote:
> Cc: Vineet Gupta <vgupta@synopsys.com>
> Cc: linux-snps-arc@lists.infradead.org
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Acked-by: Vineet Gupta <vgupta@synopsys.com> #arch/arc

Thx,
-Vineet

> ---
>
> Please ack or nack if you object to this being mered via
> Arnd's tree.
>
> arch/arc/include/asm/mmu_context.h | 17 +++++++++--------
> 1 file changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/arch/arc/include/asm/mmu_context.h b/arch/arc/include/asm/mmu_context.h
> index 3a5e6a5b9ed6..df164066e172 100644
> --- a/arch/arc/include/asm/mmu_context.h
> +++ b/arch/arc/include/asm/mmu_context.h
> @@ -102,6 +102,7 @@ static inline void get_new_mmu_context(struct mm_struct *mm)
> * Initialize the context related info for a new mm_struct
> * instance.
> */
> +#define init_new_context init_new_context
> static inline int
> init_new_context(struct task_struct *tsk, struct mm_struct *mm)
> {
> @@ -113,6 +114,7 @@ init_new_context(struct task_struct *tsk, struct mm_struct *mm)
> return 0;
> }
>
> +#define destroy_context destroy_context
> static inline void destroy_context(struct mm_struct *mm)
> {
> unsigned long flags;
> @@ -153,13 +155,13 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
> }
>
> /*
> - * Called at the time of execve() to get a new ASID
> - * Note the subtlety here: get_new_mmu_context() behaves differently here
> - * vs. in switch_mm(). Here it always returns a new ASID, because mm has
> - * an unallocated "initial" value, while in latter, it moves to a new ASID,
> - * only if it was unallocated
> + * activate_mm defaults (in asm-generic) to switch_mm and is called at the
> + * time of execve() to get a new ASID Note the subtlety here:
> + * get_new_mmu_context() behaves differently here vs. in switch_mm(). Here
> + * it always returns a new ASID, because mm has an unallocated "initial"
> + * value, while in latter, it moves to a new ASID, only if it was
> + * unallocated
> */
> -#define activate_mm(prev, next) switch_mm(prev, next, NULL)
>
> /* it seemed that deactivate_mm( ) is a reasonable place to do book-keeping
> * for retiring-mm. However destroy_context( ) still needs to do that because
> @@ -168,8 +170,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
> * there is a good chance that task gets sched-out/in, making it's ASID valid
> * again (this teased me for a whole day).
> */
> -#define deactivate_mm(tsk, mm) do { } while (0)
>
> -#define enter_lazy_tlb(mm, tsk)
> +#include <asm-generic/mmu_context.h>
>
> #endif /* __ASM_ARC_MMU_CONTEXT_H */
>