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

From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: Nicholas Piggin <npiggin@gmail.com>,
	"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	Arnd Bergmann <arnd@arndb.de>,
	"linux-snps-arc@lists.infradead.org" 
	<linux-snps-arc@lists.infradead.org>
Subject: Re: [PATCH v3 03/23] arc: use asm-generic/mmu_context.h for no-op implementations
Date: Tue, 1 Sep 2020 18:32:15 +0000	[thread overview]
Message-ID: <d6d24a21-dd08-73ad-9707-0ee341ecda7b@synopsys.com> (raw)
In-Reply-To: <20200901141539.1757549-4-npiggin@gmail.com>

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 */
>