Re: [PATCH v3 07/33] nds32: MMU initialization

[Guo Ren <ren_guo@c-sky.com>]

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