Re: [PATCH v2] riscv: make update_mmu_cache to support asid

Sergey Matyukevich
2022-09-12T07:30:42Z

Hi Jinyu,

> The `update_mmu_cache` function in riscv flush tlb cache without asid
> information now, which will flush tlbs in other tasks' address space
> even if processor supports asid. So add a new function
> `flush_tlb_local_one_page` to flush local one page whether processor
> supports asid or not,for cases that need to flush local one page like
> function `update_mmu_cache`.
>
> Signed-off-by: Jinyu Tang <tjytimi@163.com>
> ---
> RFC V1 -> V2 :
> 1.Rebased on PATCH9 of IPI imporvement series as Anup Patel
> suggestion.
> 2.Make commit log more clear.
>
> arch/riscv/include/asm/pgtable.h | 2 +-
> arch/riscv/include/asm/tlbflush.h | 2 ++
> arch/riscv/mm/tlbflush.c | 11 +++++++++++
> 3 files changed, 14 insertions(+), 1 deletion(-)

Just FYI: I have been looking into the same function w.r.t. to its
ASID/SMP handling. In addition to what your patch is doing with ASID,
I posted experimental change following flush_icache_mm approach. That
patch takes into account other concurrently running harts as well as
possible migration to other harts later on, see:

https://lore.kernel.org/linux-riscv/20220829205219.283543-1-geomatsi@gmail.com/

Regards,
Sergey