[PATCH v2 1/3] powerpc/mm: Export flush_all_mm()

[Michael Ellerman]

Frederic Barrat <fbarrat at linux.vnet.ibm.com> writes:

> With the optimizations introduced by commit a46cc7a90fd8
> ("powerpc/mm/radix: Improve TLB/PWC flushes"), flush_tlb_mm() no
> longer flushes the page walk cache with radix. This patch introduces
> flush_all_mm(), which flushes everything, tlb and pwc, for a given mm.
>
> Signed-off-by: Frederic Barrat <fbarrat at linux.vnet.ibm.com>
> ---
> Changelog:
> v2: this patch is new
>
>  arch/powerpc/include/asm/book3s/64/tlbflush-hash.h  |  8 ++++++++
>  arch/powerpc/include/asm/book3s/64/tlbflush-radix.h |  3 +++
>  arch/powerpc/include/asm/book3s/64/tlbflush.h       | 15 +++++++++++++++
>  arch/powerpc/mm/tlb-radix.c                         |  6 ++++--
>  4 files changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
> index 2f6373144e2c..c5d89d271a96 100644
> --- a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
> +++ b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h
> @@ -65,6 +65,14 @@ static inline void hash__flush_tlb_mm(struct mm_struct *mm)
>  {
>  }
>  
> +static inline void hash__local_flush_all_mm(struct mm_struct *mm)
> +{
> +}
> +
> +static inline void hash__flush_all_mm(struct mm_struct *mm)
> +{
> +}

It's not clear why it makes sense for these to be empty. Either for the
general idea of the "flush_all_mm()" API, or for your intended use by
CXL.

cheers