Re: [patch V2 00/18] mm/highmem: Preemptible variant of kmap_atomic & friends

[Thomas Gleixner]

On Fri, Oct 30 2020 at 15:46, Linus Torvalds wrote:
> On Fri, Oct 30, 2020 at 3:26 PM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> To me, your patch series has two big advantages:
>
>  - more common code
>
>  - kmap_local() becomes more of a no-op
>
> and the last thing we want is to expand on kmap.

Happy to go with that.

While trying to document the mess, I just stumbled over the abuse of
kmap_atomic_prot() in

drivers/gpu/drm/ttm/ttm_bo_util.c:      dst = kmap_atomic_prot(d, prot);
drivers/gpu/drm/ttm/ttm_bo_util.c:      src = kmap_atomic_prot(s, prot);
drivers/gpu/drm/vmwgfx/vmwgfx_blit.c:   kmap_atomic_prot(d->dst_pages[dst_page],
drivers/gpu/drm/vmwgfx/vmwgfx_blit.c:   kmap_atomic_prot(d->src_pages[src_page],

For !HIGHMEM kmap_atomic_prot() just ignores the 'prot' argument and
returns the page address. 

Moar patches to be written ... Sigh!

Thanks,

        tglx