On Mon, Aug 24, 2020 at 02:11:25PM -0700, John Hubbard wrote: > This code was using get_user_pages*(), in a "Case 2" scenario > (DMA/RDMA), using the categorization from [1]. That means that it's > time to convert the get_user_pages*() + put_page() calls to > pin_user_pages*() + unpin_user_pages() calls. > > Factor out a new, small release_registered_pages() function, in > order to consolidate the logic for discerning between > TEE_SHM_USER_MAPPED and TEE_SHM_KERNEL_MAPPED pages. This also > absorbs the kfree() call that is also required there. > > There is some helpful background in [2]: basically, this is a small > part of fixing a long-standing disconnect between pinning pages, and > file systems' use of those pages. > > [1] Documentation/core-api/pin_user_pages.rst > > [2] "Explicit pinning of user-space pages": > https://lwn.net/Articles/807108/ > > Cc: Jens Wiklander <jens.wiklander@xxxxxxxxxx> > Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx> > Cc: tee-dev@xxxxxxxxxxxxxxxx > Cc: linux-media@xxxxxxxxxxxxxxx > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx > Cc: linaro-mm-sig@xxxxxxxxxxxxxxxx > Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx> > --- > > OK, one more try, this time actually handling the _USER_MAPPED vs. > _KERNEL_MAPPED pages! > > thanks, > John Hubbard > NVIDIA Looks good and it works too! :-) I've tested it on my Hikey board with the OP-TEE test suite. I'm picking this up. Thanks, Jens
