riscv: mm: notify remote harts about mmu cache updates
Current implementation of update_mmu_cache function performs local TLB flush. It does not take into account ASID information. Besides, it does not take into account other harts currently running the same mm context or possible migration of the running context to other harts. Meanwhile TLB flush is not performed for every context switch if ASID support is enabled. Patch [1] proposed to add ASID support to update_mmu_cache to avoid flushing local TLB entirely. This patch takes into account other harts currently running the same mm context as well as possible migration of this context to other harts. For this purpose the approach from flush_icache_mm is reused. Remote harts currently running the same mm context are informed via SBI calls that they need to flush their local TLBs. All the other harts are marked as needing a deferred TLB flush when this mm context runs on them. [1] https://lore.kernel.org/linux-riscv/20220821013926.8968-1-tjytimi@163.com/ Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com> Fixes: 65d4b9c5 ("RISC-V: Implement ASID allocator") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/linux-riscv/20220829205219.283543-1-geomatsi@gmail.com/#t Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>