Subject: Re: [PATCH v3 1/2] powerpc/mm: Export flush_all_mm()

From: Alistair Popple <[email-masked]>
Date: Wed, 13 Sep 2017 14:04:35 +1000

> +static inline void hash__local_flush_all_mm(struct mm_struct *mm)
> +{
> +	/*
> +	 * There's no Page Walk Cache for hash, so what is needed is
> +	 * the same as flush_tlb_mm(), which doesn't really make sense
> +	 * with hash. So the only thing we could do is flush the
> +	 * entire LPID! Punt for now, as it's not being used.
> +	 */

Do you think it is worth putting a WARN_ON_ONCE here if we're asserting this
isn't used on hash?

Otherwise looks good and is also needed for NPU.

Reviewed-By: Alistair Popple <[email-masked]>

> +}
> +
> +static inline void hash__flush_all_mm(struct mm_struct *mm)
> +{
> +	/*
> +	 * There's no Page Walk Cache for hash, so what is needed is
> +	 * the same as flush_tlb_mm(), which doesn't really make sense
> +	 * with hash. So the only thing we could do is flush the
> +	 * entire LPID! Punt for now, as it's not being used.
> +	 */
> +}
> +
>  static inline void hash__local_flush_tlb_page(struct vm_area_struct *vma,
>  					  unsigned long vmaddr)
>  {
> diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
> index 9b433a624bf3..af06c6fe8a9f 100644
> --- a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
> +++ b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
> @@ -21,17 +21,20 @@ extern void radix__flush_tlb_range(struct vm_area_struct *vma, unsigned long sta
>  extern void radix__flush_tlb_kernel_range(unsigned long start, unsigned long end);
>  
>  extern void radix__local_flush_tlb_mm(struct mm_struct *mm);
> +extern void radix__local_flush_all_mm(struct mm_struct *mm);
>  extern void radix__local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
>  extern void radix__local_flush_tlb_page_psize(struct mm_struct *mm, unsigned long vmaddr,
>  					      int psize);
>  extern void radix__tlb_flush(struct mmu_gather *tlb);
>  #ifdef CONFIG_SMP
>  extern void radix__flush_tlb_mm(struct mm_struct *mm);
> +extern void radix__flush_all_mm(struct mm_struct *mm);
>  extern void radix__flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
>  extern void radix__flush_tlb_page_psize(struct mm_struct *mm, unsigned long vmaddr,
>  					int psize);
>  #else
>  #define radix__flush_tlb_mm(mm)		radix__local_flush_tlb_mm(mm)
> +#define radix__flush_all_mm(mm)		radix__local_flush_all_mm(mm)
>  #define radix__flush_tlb_page(vma,addr)	radix__local_flush_tlb_page(vma,addr)
>  #define radix__flush_tlb_page_psize(mm,addr,p) radix__local_flush_tlb_page_psize(mm,addr,p)
>  #endif
> diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush.h b/arch/powerpc/include/asm/book3s/64/tlbflush.h
> index 72b925f97bab..70760d018bcd 100644
> --- a/arch/powerpc/include/asm/book3s/64/tlbflush.h
> +++ b/arch/powerpc/include/asm/book3s/64/tlbflush.h
> @@ -57,6 +57,13 @@ static inline void local_flush_tlb_page(struct vm_area_struct *vma,
>  	return hash__local_flush_tlb_page(vma, vmaddr);
>  }
>  
> +static inline void local_flush_all_mm(struct mm_struct *mm)
> +{
> +	if (radix_enabled())
> +		return radix__local_flush_all_mm(mm);
> +	return hash__local_flush_all_mm(mm);
> +}
> +
>  static inline void tlb_flush(struct mmu_gather *tlb)
>  {
>  	if (radix_enabled())
> @@ -79,9 +86,17 @@ static inline void flush_tlb_page(struct vm_area_struct *vma,
>  		return radix__flush_tlb_page(vma, vmaddr);
>  	return hash__flush_tlb_page(vma, vmaddr);
>  }
> +
> +static inline void flush_all_mm(struct mm_struct *mm)
> +{
> +	if (radix_enabled())
> +		return radix__flush_all_mm(mm);
> +	return hash__flush_all_mm(mm);
> +}
>  #else
>  #define flush_tlb_mm(mm)		local_flush_tlb_mm(mm)
>  #define flush_tlb_page(vma, addr)	local_flush_tlb_page(vma, addr)
> +#define flush_all_mm(mm)		local_flush_all_mm(mm)
>  #endif /* CONFIG_SMP */
>  /*
>   * flush the page walk cache for the address
> diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c
> index b3e849c4886e..5a1f46eff3a2 100644
> --- a/arch/powerpc/mm/tlb-radix.c
> +++ b/arch/powerpc/mm/tlb-radix.c
> @@ -144,7 +144,7 @@ void radix__local_flush_tlb_mm(struct mm_struct *mm)
>  EXPORT_SYMBOL(radix__local_flush_tlb_mm);
>  
>  #ifndef CONFIG_SMP
> -static void radix__local_flush_all_mm(struct mm_struct *mm)
> +void radix__local_flush_all_mm(struct mm_struct *mm)
>  {
>  	unsigned long pid;
>  
> @@ -154,6 +154,7 @@ static void radix__local_flush_all_mm(struct mm_struct *mm)
>  		_tlbiel_pid(pid, RIC_FLUSH_ALL);
>  	preempt_enable();
>  }
> +EXPORT_SYMBOL(radix__local_flush_all_mm);
>  #endif /* CONFIG_SMP */
>  
>  void radix__local_flush_tlb_page_psize(struct mm_struct *mm, unsigned long vmaddr,
> @@ -200,7 +201,7 @@ void radix__flush_tlb_mm(struct mm_struct *mm)
>  }
>  EXPORT_SYMBOL(radix__flush_tlb_mm);
>  
> -static void radix__flush_all_mm(struct mm_struct *mm)
> +void radix__flush_all_mm(struct mm_struct *mm)
>  {
>  	unsigned long pid;
>  
> @@ -216,6 +217,7 @@ static void radix__flush_all_mm(struct mm_struct *mm)
>  no_context:
>  	preempt_enable();
>  }
> +EXPORT_SYMBOL(radix__flush_all_mm);
>  
>  void radix__flush_tlb_pwc(struct mmu_gather *tlb, unsigned long addr)
>  {
>