Hi Greentime,
On Fri, Dec 08, 2017 at 05:11:50PM +0800, Greentime Hu wrote:
[...]
>
> diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
[...]
> +void *kmap(struct page *page)
> +{
> + unsigned long vaddr;
> + might_sleep();
> + if (!PageHighMem(page))
> + return page_address(page);
> + vaddr = (unsigned long)kmap_high(page);
Here should invalid the cpu_mmu_tlb's entry, Or invalid it in the
set_pte().
eg:
vaddr0 = kmap(page0)
*vaddr0 = val0 //It will cause tlb-miss, and hard-refill to MMU-tlb
kunmap(page0)
vaddr1 = kmap(page1) // Mostly vaddr1 = vaddr0
val = vaddr1; //No tlb-miss and it will get page0's val not page1, because
last expired vaddr0's entry is left in CPU-MMU-tlb.
Best Regards
Guo Ren
